Who was the President of the United States from 1845 to 1849?

James Polk served as the President of the United States from 1845 to 1849, making him a significant figure during a pivotal period in American history. His presidency is notable for the expansion of U.S. territory, particularly through the Oregon Treaty and the Mexican-American War. Polk's administration focused on Manifest Destiny, the belief that the U.S. was destined to expand across North America. Under his leadership, the country achieved considerable territorial growth, including the acquisition of California and New Mexico, leading to intense debates about the spread of slavery into new territories. His strong executive style and commitment to fulfilling campaign promises, including his Four-point program (which promised to reduce tariffs, establish an independent treasury, oversee westward expansion, and settle the Oregon boundary dispute), helped define his presidency and the era.