1) Henry Ford developed the assembly line at his Highland Park plant in Michigan in 1913, which was the culmination of decades of technological developments. 2) Key developments included interchangeable parts, portable electric motors that allowed for flexible factory layouts, and the concept of a moving assembly line where parts were brought to stationary workers. 3) These innovations enabled Ford to realize his goal of mass production and producing affordable cars for the masses using the most efficient methods possible.

1. !1
Re-inventing the Wheel: The Technological Evolution of the Assembly Line, and
the Contributions of Henry Ford
Dr. Webb Hunter Fillers
History 4290 May 1, 2015

2. !2
Ford Motor Company opened its new Highland Park plant on the first day of 1910 as a
bastion for innovating the manufacturing process. The plant in Highland Park, Michigan
witnessed the introduction of a fully working assembly line that changed the world in 1913. The1
invention of the assembly line resulted from a technological process of growth which began
several decades earlier. Henry Ford and his group of expert managers implemented the assembly
line into production after a series of necessary technological developments of its crucial
components. How did the assembly line evolve from a pool of scattered ideas and different
technologies into a focused invention that became Ford Motor’s greatest asset? This paper will
examine the technical developments of the assembly line, and how they converged to become the
foundation of the automobile industry. The assembly line embodied the American values in the
early twentieth century of speed, standard parts, and use of space and time in an efficient manner.
From the country’s founding, the United States started tuning its culture into one focused on
speed, efficiency, and acceleration.2
Evidence suggests that the combination of Detroit, the automobile industry, and the
culture of the United States became the crucial intersection that allowed Ford Motor Company to
usher the assembly line into existence. It could have emerged earlier in another country, but this
period seems to be the catalyst for the numerous prior technological innovations to be converged
into the assembly line. The Detroit automobile industry was the perfect avenue for the assembly
line’s implementation because of those shared values of speed, interchangeable parts, and
uniformity. The industry needed the new technology, the crucial last step towards mass
David E. Nye, America’s Assembly Line (Cambridge, Massachusetts: The MIT Press, 2013), 13.1
Nye, 6.2

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production, to meet the rapidly growing demand, and that inherent need for growth led to a new
synthesis. Thomas Edison famously said, “Genius is one percent inspiration, and ninety-nine
percent perspiration.” Henry Ford perfectly personified Edison’s sentiment when it came to3
working and experimenting with machines.
Henry Ford, born in 1863, grew up on a farm in Dearborn, Michigan, and the time
working there taught him the importance of hard work even if he found it unnecessary in most
cases. Ford obsessed over the possibilities for machinery to improve the methods of farm work,
and decrease the need for manual labor indicating his early inclination towards a mechanical
nature. Even at an early age, Ford believed physically demanding labor should be replaced with a
more efficient machine whenever possible. Ford began thinking about how machines4
functioned, and opportunities for their improvement stating that the best way to learn is, “simply
by tinkering with things. It is not possible to learn from books how everything is made and a real
mechanic ought to know how nearly everything is made. Machines are to a mechanic what books
are to a writer. He gets ideas from them, and if he has any brains he will apply those ideas.”5
Before standard time went into effect the railroads used a different clock than local time. Ford,
who worked at a watch and jewelry repair shop at this time, disliked the lack of standard time,
and built a two dial watch that offered both local and railroad time together. This example of his
early knack for invention indicated Ford’s proclivity for standardization, and an interest in
building machines that achieved maximum efficiency. The automobile had yet to pique Ford’s
M.A. Rosanoff, “Edison In His Laboratory,” Harper’s Magazine, September 1932, 406.3
Steven Watts, The People’s Tycoon: Henry Ford and the American Century (New York: A.A. Knopf, 2005), 15.
4
Henry Ford and Samuel Crowther, My Life And Work (Garden City, New York: Doubleday, Page, and Company,1922), 24.5

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curiosity, but his future motivations to attain mass production and efficient manufacturing can be
traced back to those early formative years.6
In 1890, Ford began experimenting with gas powered engines believing them more
suitable for developing a horseless carriage than steam power. He got a job at Detroit Edison
Company, and spent all of his nights after work on building an engine from beginning to end.
Two years of tireless work later the engine had been completed. Reflecting on those long nights
spent in the shed behind his home Ford remarked, “I cannot say it was hard work. No work with
interest is ever hard. I always am certain with results. They always come if you work hard
enough.” Ford completed the engine in 1893, and ran it over 1,000 miles before he sold it for7
$200. Ford never intended on building his engine to make a profit, but he quickly realized it
would subsidize more experiments and improvements, after all, his ultimate focus remained on
mass production. In 1899, Ford faced a decision when his employers, Thomas Edison excluded,
offered an ultimatum between moving up the corporate ladder or continuing his automobile
work. Ford stated, “There was nothing in the way of a choice. For already I knew the car was8
bound to be a success.” Ford left just as his career started to blossom, and forayed into the9
automobile business. A decision that forever altered the future of the automobile industry and
America. Ford improved his prototype, termed the “Quadricycle”, to a suitable point for public
use, but starting a business involving the manufacturing of automobiles on a large scale required
Ford and Crowther, 25.6
Ibid. 30.7
Watts, 46.8
Ford and Crowther, 35.9

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substantial financial resources and organization. Henry Ford needed to transform himself from a
successful inventor into a successful businessman to secure them.10
For the next several years Ford led two distinct lives, one where he experimented and
improved his prototypes with hopes of mass producing an automobile for any person who
wanted to buy one, and the other spent seeking financial backing for his company to actually
begin production. Luckily for him, financial backing proved plentiful at the turn of the twentieth
century affording many opportunities for upstart projects. Ford learned about running a11
business by “tinkering” as he did with machines, and noticed two points that surprised him.
Ford’s first contention, “was the large attention given to finance and the small attention to
service… The money should come as a result of work and not before the work…The second
feature was the general indifference to better methods of manufacture as long as whatever was
done got by and took the money.” Both of these viewpoints were contrasted by Ford throughout12
his career as he always searched for the best manufacturing methods available, and supported
fair wages for fair work. Ford’s focus on getting his invention to market remained intact, but he
faced failure several times brought on by his reluctance to accept those business practices of the
time. Rarely do people get second chances in business, or in Ford’s case a third chance, but
passion and belief in his work drove him to eventual success.13
Watts, 49.10
Ibid. 52.11
Ford and Crowther, 37-38.12
Watts, 63.13

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Charles E. Sorensen, Ford’s confidant for over forty years at the company, described two
events in 1903 that changed the world, “Wilbur and Orville Wright were the first human beings
to fly a heavier-than-air-machine [and] in Detroit, Ford Motor Company was incorporated…
destined to make motor transport universal, to attain mass production, to demonstrate the
superiority of an economy of abundance over one of scarcity.” Henry Ford’s ability for finding14
the most talented, hardworking managers proved excellent, but his willingness and knowledge of
which jobs to delegate to them became his most beneficial trait. Ford Motor Company saw a
growth spurt between 1903 and 1905, and many of Henry Ford’s hirings during this time laid the
foundation for the company’s monumental success over the next few decades. Although Ford15
became a proficient overseer and delegator it remained clear to all of his associates that he
maintained the final say in all important decision.
The business side of Ford Motor Company became an area where Henry Ford’s
contribution shrank, and he gave most authority to a new associate, James Couzens, who turned
out to be a godsend for the accounting of the company. Couzens talent soon overflowed the
confines of his position, and he dominated all business operations. His contributions to the
company placed him only below Henry Ford as the most influential employee of Ford Motor
Company. Charles Sorensen went as far as defining the period from 1903 to 1913 as the16
“Couzens Period” and asserted that, “Ford Motor Company would not have made cars for long
without James Couzens… Everyone in the company, including Henry Ford, acknowledged him
Charles E. Sorensen and Samuel T. Williamson, My Forty Year with Ford (New York: Norton, 1956), 35.14
Watts, 90.15
Ibid. 91.16

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as the driving force during this period.” The company saw much success behind Couzen as17
general manager and Ford as organizer of manufacturing. Ford Motor Company had proven itself
as a leader in the industry. Demand, sales, and profits increased significantly by 1908, but Henry
Ford set his eyes on a new goal: developing a plant focused on true mass production. Ford began
searching for a way to make an affordable automobile for the common man. In order to lower18
prices the company needed to eradicate as many inefficiencies as possible from the production
process, and the beginning ideas for what became the assembly line started to form inside Ford
Motor Company.
Ford Motor company firmly established itself financially by 1908, and the only issues it
faced were limited to production and expansion. The Highland Park Plant opened on January 1,
1910 as the largest automobile plant in the world, and with it came the expansion of
manufacturing. Within the next year factory space increased from 2.65 acres to 32 acres,
employees from 1,800 to over 4,000, and Model T output from 6,000 to 35,000 cars produced.
Demand soared due to slightly lowered prices while production began to stagnate.19
Comparatively, the task of building a car proved much simpler than the process of transferring
materials from the stockroom to the assembly location. Charles Sorensen worked to alleviate this
problem for some time when the idea struck him that, “assembly would be easier, simpler, and
faster if we moved the chassis along, beginning at one end of the plant with a frame and adding
the axles and the wheels; then moving it past the stockroom, instead of moving the stockroom to
Sorensen, 36.17
Watts, 106.18
Ford and Crowther, 74.19

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the chassis.” Ford offered encouragement for the crudely crafted version of the early assembly20
line, simply a rope pulling a chassis past parts placed on the floor, but he remained skeptical. The
Ford plant at Highland Park gave the company enough space to experiment with new technology,
and focus on improving their assembly line concept. Henry Ford and associates began
investigating the manufacturing industry for the best methods and technologies available to
create the most efficient means of production possible.
Interchangeable parts became a vital component of the assembly line which allowed for
uniform parts that need no further alterations once they are manufactured. This allows for a
finished part to be sent for assembly by a worker with the exact specifications needed for that
job. The first conception of the idea can be traced to eighteenth century France when Honoré
Blanc, a gunsmith under sponsorship from the government, began experimenting with methods
to produce muskets more efficiently and cheaper than previously possible. Blanc proposed a
state-run workshop with a focus on uniform production and interchangeable parts.21
Interchangeable parts stagnated in France because Blanc’s method was years out from producing
true uniformity, but Thomas Jefferson, the United States Minister to France, saw the possibilities
of the emerging idea. In a 1785 correspondence with John Jay, Jefferson reported about an
improvement in construction of muskets that may be of interest to Congress. Jefferson noted,
“Supposing it might be useful to the U.S., I went to the workman, he presented me the parts of
Sorensen, 117.20
Ken Alder, “Innovation and Amnesia: Engineering Rationality and the Fate of Interchangeable Parts Manufacture21
in France,” Technology and Culture 38 (February 1997): 273.

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50. locks taken to peices [sic], and arranged in compartments. I put several together myself
taking peices [sic] at hazard as they came to hand, and they fitted in the most perfect manner.
The advantages of this, when arms need repair, are evident.”22
Eli Whitney became a major proponent of interchangeable parts in the United States, and
received a contract to work on making it a viable method for use on a large scale in 1798.
Whitney was unable to produce the precision that was necessary for interchangeable parts, and
he never achieved the level of success witnessed by Samuel Colt and weapons makers later in the
nineteenth century. The development of interchangeable parts as used on the assembly line by23
Ford Motors can be traced through the nineteenth century as a thread of progress weaving in and
out of different types of manufacturing while being tweaked and improved at each destination. It
began with Eli Whitney then onto the success of Federal arsenals, privately owned New England
gun producers such as Samuel Colt, and finally sewing machine and bicycle makers before the
final version became a key in Henry Ford’s vision of mass production. Adoption of the armory24
practice which used specialized machines to produce each part rather than adjusting a single
machine for many different parts allowed the managers at Ford to set a new standard for quick
and precise uniformed parts. An efficient use of interchangeable parts was the first step in
creating a viable assembly line, but other technologies would need to be entered into the equation
before it could be developed for use in large scale production at Highland Park.25
Thomas Jefferson to John Jay, August 30, 1785, in The Papers of Thomas Jefferson, ed. Julian P Boyd, 8:22
452-456.
Nye, 24.23
Alder, 274.24
Nye, 25.25

10. !10
Many factories at the turn of the century used steam power as an energy source. This
meant that the layout of the average factory, with a centrally located power source, became a
hurdle in the way of the assembly line. Most machines had strict positions so that the energy
could reach them physically by means of gears, belts, and shafts. As factories grew larger so did
the need for power to move all the physical parts, and the machines needed to be in precise
locations in order to function. The assembly line would need a more mobile power supply so26
machines could be moved and placed freely throughout a factory. Once again a technological
innovation in the form of portable electric motors became a necessity for a working and efficient
assembly line. The first big breakthrough in electric motor development occurred in 1839 when
Moritz von Jacobi produced a motor powerful enough to move his twenty-eight foot boat across
the Neva River in Russia. The boat carried fourteen passengers, and crossed the river against a
strong current at three miles per hour. Jacobi achieved this feat by employing his theory, later
known as Jacobi’s Law, which stated, “"The mechanical work given out by a motor is a
maximum when the motor is geared to run at such a speed that the current is reduced to half the
strength that it would have if the motor was stopped." In simpler terms, the theory rationalized27
that a motor would lose half of its energy output in an effort to produce maximum power.
Jacobi’s Law was an important step toward the electric motors used at the start of the nineteenth
century, but it focused on maximum power rather than efficiency.
The electric motor continued its development, and reached a point in its progression
where it made sense for the outfitting of factories. Adoption of electric motor use began
Ibid. 18.26
Silvanus P. Thompson, Dynamo-electric machinery: A Manual for Students of Electrotechnics (London: E. & F.N. Spon Press,27
1886), 406.

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increasing in 1900, and by 1910 almost twenty percent of all factory power in the United States
came from the new source of energy output by the emerging technology. The possibility of28
shaping a factory’s layout to match the job needed became a preferred reality to the former
method of creating a job to fit the placement of a machine. Once distance ceased to be a factor in
factory layouts, newly built factories could be formed with an open space format without the
need for a power source located in the center. Ford took advantage of this new development by
fitting each machine with its own electric motor to obtain the ultimate maneuverability in its
factories which allowed more flexibility, and encouraged innovation. This concept proved vital
in the process of creating the assembly line, and became a key feature of Ford’s Highland Park
plant in 1910.29
One of the last technical innovations needed for the assembly line may be the most
obvious when discussing its development. The automatic and continuous movement of parts
down the line from one assembly site to the next proved to be integral to the whole operation.
Primitive conveyor belt systems had been used in a multitude of industries throughout the
nineteenth century including bakeries breweries, and cigarette plants. Meat packing plants began
using a similar method around 1850 for the purpose of disassembly. Thomas Robbins, a rubber
products salesman, began working toward the modern conveyor belt system in 1892 which
would later be used in the assembly line in 1913. Robbins’ concept caught the attention of
Thomas Edison who installed the system in his iron mining facility in New Jersey. Henry Ford
and Edison fostered a friendly relationship after they met during Ford’s days at Detroit Edison
Richard B. Duboff, Electric Power in American Manufacturing, 1889-1958 (New York: Arno Press, 1979), 82.28
Nye, 19.29

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Company. Ford observed the conveyor process during a visit to Edison’s facility from which he
returned with a better understanding for processing and handling materials. Historian Richard30
Arms examined the advantages of constantly moving parts and determined that, “In terms of
manpower and technique, the problem of the assembly line reaches a solution when the worker
no longer has to substitute for any movement of the machine, when he simply aids production as
a watcher and tester.” The use of conveyor belts and gravity slides decreased strain by bringing31
the job to the workers, saved space on the factory floor, and greatly improved efficiency in
Ford’s inventory management by eliminating downtime when parts were stopped on the line.
After Ford installed the new conveyor belt system the distance that parts travelled shrank
substantially. Previously an engine block traveled 4,000 feet in the factory, but under the new
system it only needed to move 334 feet for assembly. Conveyor belts added tremendous32
benefits to workers, inventory management, and production times. As a car moved down the
conveyors of Ford’s assembly line they were pieced together as parts came in from adjacent
lines. A single part would take a man an eight hour workday to manufacture what the assembly
line produced in one minute. It became instrumental in providing a simple, but vital
technological innovation to the assembly line.33
Ford Motor Company spent several years researching, testing, and buying any piece of
machinery they thought might improve production times which led to substantial increases in
Ibid. 27.30
Richard G. Arms, “From Disassembly to Assembly: Cincinnati: The Birthplace of Mass-Production,” Bulletin of31
the Historical and Philosophical Society of Ohio 17 (1959): 195.
Nye, 27.32
Henry Ford, “Henry Ford Expounds Mass Production,” New York Times, September 19, 1926.33

13. !13
efficiency. According to Charles Sorensen, “We extended the conveyor belt system to other parts
assemblies and set our sights on turning out 200,000 cars the next year… the rate of one car
every two minutes.” In January of 1914, the fourth anniversary of the Highland Park Plant’s34
opening, the fully functioning assembly line became a reality. Interchangeable parts, portable
electric motors, and a modernized conveyor belt system were all implemented into Ford Motor
Company’s assembly line, and together they helped revolutionize production methods. A new
industrial revolution occurred once the assembly line emerged from testing, and Henry Ford’s
long held vision of mass production transformed from an idea into an attainable goal. The new
technology allowed Ford Motor Company to sell its product cheaper than the competition and
raise wages while profits continued to soar. The assembly line offered benefits to consumers,
producers, and workers that no production technology had ever achieved. Ford Motor’s assembly
line improved production drastically, reducing the time to assemble a Model T from 12 hours to
just 93 minutes, and allowed the same number of workers an increase in output of 775% in a
similar timeframe. As a result of the implementation of assembly line technology production35
dramatically increased, but the mass production process itself is more important than the shear
volume of production alone. Ford realized that mass production is a method in its own right, and
the assembly line became a conduit to achieve more efficient production. Ford’s idea of mass
production involved three major components, “The planned orderly progression of the
commodity through the shop; The delivery of work instead of leaving it to the workman's
initiative to find it; An analysis of operations into their constituent parts….All three
Nye, 130.34
Ibid. 29.35

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fundamentals are involved in the original act or planning a moving line of production.” These36
principles of mass production, explained by Ford, are highly dependent on a efficient use of the
assembly line. Mass production entered uncharted territory, and its effects on the automobile
industry, the economy, and the country ensured that the future course of the United States would
be completely altered.
Ford Motor Company entered into a new era of industrialization, and the public
feverishly accepted this new future of mass production. Newspapers and magazine articles
greatly stimulated public interest in the assembly line, and by 1915 the numerous accounts in
books and periodicals were insufficient to satiate the public’s hunger to see it in action. Soon the
Highland Park Plant hired twenty-five tour guides to work full time, and give the awestruck
visitors a glimpse at the modern marvel. Paul Lowry, a writer for the Los Angeles Times,37
reflected after a visit to the Highland Park Plant that, “No trip to the factory district of Detroit
would be complete without a visit to the birthplace of the Ford, which employs 51,000 men and
turns out vehicles at the rate of 49,000 a day, is to Detroit what the Woolworth Building is to
New York. It stands out like a beacon in the fog.” The public perception of the assembly line38
made it a tourist attraction as much as it had become a revolutionary technology. When the
endless flow of visitors began to distract the workers on the assembly line, Henry Ford allowed
so many tourists in the plant that the novelty for workers ceased, and eventually workers stopped
“Henry Ford Expounds.”36
Nye, 45.37
Paul Lowry, “Men Swarm Like Bees in the Ford Factory,” Los Angeles Times, February 4, 1923.38

15. !15
acknowledging the tour groups. Henry Ford set up an operating assembly line at the San39
Francisco World’s Fair in 1915 which produced a Model T every ten minutes to be driven off the
line to a nearby Ford distributor. It became the most popular exhibit at the World’s Fair as
thousands of eager visitors lined up each day to witness the display, and proved the assembly
line’s ability to attract the attention of the general public.40
Evidence indicates that the assembly line developed out of a need to meet demand, and
that it became possible due to the combination of past technological developments rather than a
sudden spark of genius from any one entity. The prior developments of interchangeable parts,
electric motors, and conveyors all fed into the assembly line to support the emerging technology,
mirroring the process of the parts that traveled down the conveyors and fed into final assembly at
the Highland Park Plant. David Nye explains that, “The assembly line is best understood not as a
rigid system...but rather as a moment of synthesis for a still-evolving processing technology.”41
Henry Ford’s role in the assembly line’s implementation proved vital since Ford Motor
Company, the Highland Park Plant, and a necessity for mass production to flourish were brought
to life from his passion and early determination. However, Ford did not directly create the
assembly line himself, but instead he sponsored its creation by delegating power to his many
talented associates at the company as he oversaw their work. He allowed the creativity of those
around him to set the course for the automobile empire which he started, and the company
William Littman, “The Production of Goodwill: The Origins and Development of the Factory Tour in America.”39
Perspectives in Vernacular Architecture 9 (2003), 80.
Nye, 45.40
Ibid. 38.41

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prospered because of his willingness to trust them. The United States’ culture in the early42
twentieth century played a major role in shaping mass production with its focus on speed,
standardization, and efficiency. In return, mass production offered the country a chance for
greater social progress as wages increased, more jobs were created, and prices fell. The assembly
line opened the pathway to mass production, and simultaneously changed the function of
industry and the world.
Sorensen and Williamson, 116.42