Completion of the Erie Canal inaugurated a new era in the growth of New York City, Buffalo, and numerous other communities of New York State. With the increase in goods and capital, New York City cemented its role as the leading financial and commercial center in the nation, surpassing other eastern cities such as Boston and Philadelphia.
Partly due to the canal, the population of New York City grew from 123,706 in 1820 to 696,115 in 1850. Large areas within and outside of the state were opened up for settlement. For many years, however, the Erie Canal served as the chief traffic artery, for both passengers and freight traveling between the Northeast and what was then the West.
Between 1861 and 1914 almost 30 million people came from Europe to the United States. This increase in immigration to the United States had many effects.
Immigrants came to New York in the 1800s from many different places and for many different reasons. English, French, and Germans fled poverty and looked for opportunity. But mostly they came from Ireland and for the simplest of reasons: they were starving to death. The potato crop was failing, and English masters were taxing away their money. America seemed their only hope.
Some German immigrants joined the Irish and in working the city's docks, streets, factories, and construction sites. They worked on the Erie Canal—helping further America’s growth. They also worked in the factories in the North.
Several countries in South American had recently undergone revolutions against their European colonial owners and ended up with republican governments. The United States agreed with their political philosophy and did not want to see those newly free nations become European colonies again.