EXPANSIONISTS

Soon after the colonies won the American Revolution (1775–83) and founded the United States of America, nationalist fervor emerged. Eager to spread "American ideals," expansionists looked westward, northward, and southward to expand the territory of the Union beyond the original 13 states. They favored the settlement of the frontier—some advocated seizure of the Southwest (from Spain and later from Mexico), Florida (from Spain), the Louisiana Territory (from France), and the Northwestern Territories and even Canada (from Britain). By the 1840s the doctrine of Manifest Destiny took hold. (A doctrine which held that the United States had a God-given right and duty to expand its territory and influence throughout North America).

The fires of expansionism were fueled by population growth during the 1800s. Pioneer settlement of the Plains and the Old Northwest (present-day Ohio, Michigan, Indiana, Illinois, Wisconsin, and part of Minnesota) resulted in an increase in farmland and overall crop production. Inventions such as the cotton gin and the McCormick reaper improved the processing and harvesting of raw materials such as cotton and grain, and a continuous influx of immigrants from Europe supplied labor for the factories that had opened across New England and the Mid-Atlantic. All these factors combined to create a rapid population growth. In the two decades between 1840 and 1860 alone, U.S. population more than doubled, increasing from about 17 million to more than 38 million. Though the eastern seaboard cities grew, a system of new canals, steamboats, roads, and railroads also opened up the interior to increased settlement. By 1850 almost half the population lived outside the original 13 states.

Though Canada remained in the hands of the British, the spirit of expansionism resulted in a rapid acquisition by the United States of North American territories that had belonged to Spain, Mexico, France, and England. By 1853 the United States owned all the territory contained in the present-day contiguous states. By the end of the century, the United States owned all the territory of its present-day states— which included Alaska (purchased from Russia in 1867) and Hawaii (annexed in 1898).

See also: Alaska, Hawaii, Manifest Destiny, Old Northwest, James Polk