Entering politics as a Whig, Foot served in several offices, including member of the Vermont House of Representatives, delegate to the state constitutional conventions of 1833 and 1836, and Rutland County State's Attorney. He was Vermont's Speaker of the House from 1837 to 1839. Foot served in the United States House of Representatives from 1843 to 1847 and was noted for his opposition to the Mexican–American War and the extension of slavery. He did not run for reelection in 1846; returned to the Vermont House, he served as Speaker from 1847 to 1848.