James K. Polk, President (usa) : All Data

James K. Polk was the 11th President of the United States, serving from 1845 to 1849. During his presidency, he oversaw the Mexican-American War (1846-1848), which resulted in the acquisition of vast territories in the Southwest, including California and New Mexico. Polk's administration also witnessed the Bear Flag Revolt (1846) in California, where American settlers declared independence from Mexico, and the Oregon boundary dispute with Britain, which was resolved through the signing of the Oregon Treaty in 1846. As a determined expansionist, Polk's presidency was marked by territorial gains and the establishment of the United States as a continental power.