This paper explains that the American Revolution secured America's freedom, and the Louisiana Purchase led to the great Westward
Expansion and Lewis and Clark's expedition, giving enough room for the
country to grow and to expand the economy with agriculture and natural resources found in the West. The author points out that the Civil War eventually ended
slavery and was the catalyst for bringing the country back together after the South succeeded from the North. The paper relates that the fourth most important event of this period was the continued immigration of foreigners, which created the melting pot culture of America.