What was the role of James K. Polk in 1846?

In 1846, James K. Polk served as the 11th President of the United States and played a pivotal role in the outbreak of the Mexican-American War. He was a strong proponent of westward expansion and the concept of Manifest Destiny, seeking to acquire California and New Mexico. His administration's desire to expand U.S. territory led to tensions with Mexico, ultimately resulting in armed conflict after Polk's assertion that Mexican forces had attacked American troops on disputed land. This war significantly increased U.S. territory and shaped the nation's future.