During the Mormon War of 1838, Price served as a member of a delegation sent from Chariton County, Missouri to investigate disturbance between Latter Day Saints and anti-Mormon mobs in the western part of the state. He reported the Mormons were not guilty of any offenses. Also, that the charges against them were false. Following the Mormon surrender in November 1838, Missouri governor Lilburn Boggs sent Price and a company of solders to protect the Mormons. Price was elected to the Missouri State House of Representatives from 1836–1838, and again from 1840–1844. He was chosen as its speaker. He was then elected as a Democrat to the 29th United States Congress, serving from March 4, 1845, to August 12, 1846. He resigned from the House to participate in the Mexican-American War.