The Louisiana Purchase
• Purchased by Thomas Jefferson from France
for $15 million in 1803 money.
• Jefferson was uneasy about France and Spain
being able to block US trade to New Orleans.
• Doubled the size of the United States.
• Largely unknown territory.
• Jefferson thought there could be a waterway
that connected to the Pacific Ocean.
Were there earlier expeditions in
western North America?
• Lewis and Clark were the third recorded
expedition across North America.
• Sir Alexander Mackenzie crossed North
America in 1789.
• Cabeza de Vaca reached the Pacific Ocean in
1536 with three others with the Narváez
Corps of Discovery
• Scientific and Military expedition to explore
the newly acquired Louisiana Purchase.
• Made up of Meriwether Lewis and William
Clark plus 31 other men.
• Were supposed find a water passage from the
United States to the Pacific Ocean for
commerce and communication.
• Also to study the natural resources of the
• Born in Virginia in 1774.
• Had skills of an outdoorsman.
• Joined the US Army in 1795 until 1801.
• Was an aide to President Jefferson and
resided in the presidential mansion.
• Was chosen by Jefferson to lead an expedition
to explore the recently purchased Louisiana
• Also born in Virginia in 1770.
• Chosen by Meriwether Lewis to help lead the
Lewis and Clark Expedition.
• Afterwards he was the territorial governor of
• Served as the Superintendent of Indian
The Start of the Expedition
• Meriwether Lewis departed Pittsburg,
Pennsylvania on August 31, 1803, which was
the true start of the expedition.
• The expedition departed Camp Dubois in the
Illinois Territory and followed the Missouri
• After departing St. Charles the expedition passed La
Charrette, which was the last white settlement on
• Lewis and Clark passed through what is now Kansas
City, Missouri and Omaha, Nebraska and camped at
the confluence of the Missouri and Kansas Rivers.
• Sergeant Charles Floyd died of acute appendicitis on
August 20, 1804. The first death for the Corps of
Encounters with Natives
• Lewis and Clark encountered many natives
along the Missouri River.
• The Yankton Sioux were the first tribe they
encountered and were for the most part
• The Lakota tribe was much more hostile and
demanded a boat from the expedition.
• The Corps were prepared to fight back when
the Lakota pulled back.
• During the winter of 1804-05 the expedition
built Fort Mandan.
• It was here Lewis and Clark employed a
French fur trapper and his young Shoshone
• Sacagawea served as a translator and
sometimes a guide for the expedition.
Crossing the Rockies
• Lewis and Clark crossed over the Continental
Divide at Lemhi Pass.
• The expedition thought they would cross the
Rockies in a day but it turned into an 11 day
• Americans were not aware of the size of the
The Pacific Ocean
• After crossing the Rocky Mountains the Corps
of Discovery made their way towards the
• They followed the Columbia River past
present day Portland, Oregon and eventually
to the Pacific Ocean.
• The party built Fort Clatsop, near present day
Astoria, Oregon, as their winter camp.
• On their journey home Lewis and Clark used four
dugout wood canoes.
• After an encounter with the Blackfeet natives in
which two natives were killed.
• Lewis and Clark separated fleeing the Blackfeet and
were reunited at the confluence of the Yellowstone
and Missouri Rivers.
• After reuniting the Corps of Discovery followed the
Missouri River back to St. Louis on September 23,
• Lewis and Clark filled in a large blank space on
the map of North America, which had not
previously been mapped.
• The expedition documented 178 plants and
122 species of animals, including a Prairie Dog
which was sent to Thomas Jefferson alive.
• The Corps also established somewhat cordial
relations with Natives in the area.