During Monroe's presidency, five new states had joined the Union: Mississippi (1817), Illinois (1818), Alabama (1819), Maine (1820), and Missouri (1821). Twenty-five percent of the American population was living west of the Appalachians by 1820. According to the Land Act of 1820, farmers could buy eighty acres at $1.25 per acre with a down-payment of $100 in cash. At such prices, nearly 3.5 million acres of land were purchased in 1820 alone, although not all of these sales reflected actual settlement. Land speculation in the West was uncontrolled, as wealthy investors bought giant tracts for resale to farmers and migrants. For these western settlers, the major political issues reflected their need for easy credit to clear the land, good transportation routes to move their products to market, debt relief, and cheap manufactured goods for them to consume.

Although the new states gave a western slant to American politics, most of the settlers still tended to identify with the regions from which they had recently migrated. Importantly, most Americans still thought of themselves as Americans first. With this strongly nationalist temperament, most Americans were swept up in the changes in transportation that began to revolutionize travel and the movement of goods, as well as by the effects of the so-called market revolution. By 1820, there were sixty steamboats on the Mississippi River alone; dozens more operated on the Hudson River and the Great Lakes. James Monroe was the first President to travel on a steamboat, which he did in 1817. That year, Monroe's first as President, the New York legislature authorized funding to build a canal linking the Hudson River with Lake Erie, thus opening a continuous water route connecting the Northwest to New York City. The Erie Canal, a giant ditch stretching 364 miles from Albany to Buffalo that was completed in 1825, was built by thousands of Irish immigrants, local farm boys, and convict laborers.

Economic Changes

In New England, a new system of factories, using steam-driven looms, began employing thousands of local farm girls in the production of cloth. In the New England countryside, moreover, farmers began raising livestock and consuming store-bought goods such as sugar, salt, coffee, sacks of western flour, silverware, and dishes. Urban centers of industry were also being transformed. New York City, for example, became the center of a national market of ready-made clothes in the 1820s. The city's manufacturing success was built upon the new supplies of cheap cloth, an expanding supply of female labor, and the emergence of southern and western markets that were accessible via coastal and overland trade routes. Thousands of women worked in sewing to crudely assemble "Negro cottons" for shipment to southern planters as slave clothing. By 1825, shoemakers in Massachusetts manufactured barrels of shoes—uniform in size—for shipment to the slave South.

Below the Mason-Dixon surveyor's line, which separated the borders of the slave South from the North, the invention of the cotton gin in 1793 had revolutionized southern agriculture. By the mid-1820s, cotton and plantation slavery were beginning to dominate the most fertile lands stretching from Georgia to Mississippi. Wealthy planters lived in richly furnished plantation mansions and had begun to create a lifestyle of white mastery over black slaves that shaped every aspect of southern life.

As the market revolution transformed subsistence farmers into commercial farmers who specialized in crops for sale, the average size of the American family began to decline from 6.4 children to 4.9 children; this was especially noticeable in the more commercialized farming areas of the North. Also, women began to labor more intensively in new kinds of household work. Store-purchased white flour and new iron stoves created demands for home-baked cakes, pies, and other fancy goods that had rarely graced the subsistence farmer's table prior to 1820. More and more farm families kept cleaner houses, painted them, and forbade spitting tobacco on parlor floors.