History of the United States (1815–1849) in the context of Internal improvements

The history of the United States from 1815 to 1849—also called the Middle Period, the Antebellum Era, or the Age of Jackson—involved westward expansion across the American continent, the proliferation of suffrage to nearly all white men, and the rise of the Second Party System of politics between Democrats and Whigs. Whigs—representing merchants, financiers, professionals, and a growing middle class—wanted to modernize society, using tariffs and federally funded internal improvements; Jacksonian Democrats opposed them and closed down the national bank in the 1830s. The Jacksonians favored expansion across the continent, known as manifest destiny, dispossessing Native Americans of lands to be occupied by farmers, planters, and slaveholders. As a result of the annexation of Texas, the defeat of Mexico in war, and a compromise with Britain, the western third of the nation rounded out the continental United States by 1848.

The transformation America underwent was not so much political democratization but rather the explosive growth of technologies and networks of infrastructure and communication, including with the telegraph, railroads, the post office, and an expanding print industry. These developments made possible the religious revivals of the Second Great Awakening, the expansion of education, and social reform. They modernized party politics and sped up business by enabling the fast, efficient movement of goods, money, and people across an expanding nation. They transformed a loose-knit collection of parochial agricultural communities into a powerful cosmopolitan nation. Economic modernization proceeded rapidly, thanks to highly profitable cotton crops in the South, new textile and machine-making industries in the Northeast, and a fast developing transportation infrastructure.