The Westward Expansion has often been regarded as the central theme of American history, down to the end of the19th century and as the main factor in the shaping of American history. As Frederick Jackson Turner says, the greatest force or influence in shaping American democracy and society had been that there was so much free land in America and this profoundly affected American society.
After the revolution, the winning of independence opened up the Western country and was hence followed by a steady flow of settlers to the Mississippi valley. By 1840, 10 new western states had been added to the Federal union. The frontier line ran through Iowa, Missouri and Arkansas on the western side of the river.
All parts of the valley except Wisconsin and Minnesota were well populated. Thus a whole new section had been colonized with lasting effects on the American institutions, ideals and ways of living.
The far west was the land of high mountains, deserts, strange rock formations, brilliant colors and immense distance. Fur trade with Europe had now become a lucrative business and the fur traders became the pathfinders for the settlers. Migration was now possible by the discovery of paths over which ox-driven carts could be driven through seeking mountains and across the western desert. People wanted to move away from the overcrowded cities and this led to the migration into the uninhabited lands.
Increased transportation like roads, railroads and canals and their construction created a demand for cheap labor making it easier for people to get jobs now, in contrast with the cities where there was unemployment.
The pioneer movement for 70 years after the revolution roughly represented the form of 3 parallel streams, flowing westwards from New England, Virginia and South Carolina. The first pioneer groups tended to move directly westward. Thus the new Englanders migrated into western New York and along the shores of the great lakes, Virginians into Kentucky and then into Missouri and the South Carolinians and Georgians into the gulf territories. Throughout the settlement of the Mississippi valley, most pioneers did not travel long distances and as a territory had been occupied, families would move into the adjacent one.
There were boom periods of great activity, during which million acres of land were sold, alternated with depression periods during which there was little further expansion of the frontier and many disappointed pioneers even backtracked from the west to the east.
When the treaty of Paris was signed in 1783, the Americans had thought that they had enough land between the Atlantic coast and the Mississippi river. Yet in 1803, by the Louisiana Purchase, the area of the United States doubled and not long after, it was augmented by the half-purchase-half-conquest of Florida. By the end of 1820, as many as 6 states were created, east of Mississippi-Indiana (1816), Mississippi (1817), Alabama (1819), Maine (1820) and Missouri (1821). By the 1830s, the frontier line had been carried to Iowa, Missouri and Arkansas-about one-third of the way across the continent.
By the 1840s, the expansionist policy, typified by the Manifest Destiny doctrine, became very strong with many sections willing to go to war to acquire more land. Slavery became a bone of contention between the Northern and southern states with the control of the senate in question.
The South wanted expansion to increase slave states, the North to keep the balance with free states and the West wanting expansion to increase their land. The antagonism between the North and the South sees the beginnings of sectionalism leading to the civil war later. The spirit of equality becomes a banner with which the expansionist policy was proclaimed.
Before the 1830s, most sections of the west passed through the same phases of development in a regular order. The first white men to usually enter a new area were the hunters and fur trappers, who had extraordinary skills to open up a new path through wilderness, finding food for themselves and dealing with the Indians. These men explored the country and brought news of its resources back to the east.
In many regions, the second phase was cattle ranching while some also passed through the mining phase. Parts of Missouri and Wisconsin, for example were settled .