Born November 10, 1813, in Fayette County, Pennsylvania. Mr. Thompson attended the common schools and when twenty-one began to study law in the office of Columbus Delano. In 1839, he went by steamboat down the Ohio River and up the Mississippi River to Montrose in what was then Iowa Territory, before settling in what is now Mount Pleasant, Iowa. He married Harriet Roberts in Henry County, Iowa on February 4, 1845. In 1843, he was a member of the Iowa Territory House of Representatives. He served as chief clerk of the two succeeding sessions, and became secretary of the 1846 Iowa state constitutional convention. Iowa was admitted to the union effective December 1846, and given two seats in the U.S. House. The First Iowa General Assembly established the boundaries of those districts in February 1847, and set elections for August 2, 1847 to name their representatives in the Thirtieth Congress (from December 1847 to March 1849). Mr. Thompson, running as a Democrat, defeated Whig Party candidate J.B. Browne by 544 votes. The legality of Iowa’s 1847 congressional elections was questioned because Iowa Governor Ansel Briggs never signed the law authorizing the elections, but the U.S. House nevertheless seated the winners. In 1848, Mr. Thompson was re-nominated, and ran in the August general election against Whig Party member Daniel F. Miller. He was certified as the winner by the Iowa Secretary of State and upon presenting his credentials to the U.S. House was initially allowed to continue representing his district. For several years he was editor of the Iowa State Gazette. He was elected chief clerk of the Iowa House of Representatives in 1861, by a unanimous vote. On July 31, 1861, after the outbreak of the Civil War, Mr. Thompson was commissioned as a captain in Company E of the 1st Regiment Iowa Volunteer Cavalry. On May 18, 1863, he was promoted to major, and on June 20, 1864, to colonel. On March 13, 1865, as the end of the war approached, he became a brevetted brigadier general of the Volunteers. When the Civil War ended, his military service did not. On July 28, 1866, at the request of General George Custer, he was recommissioned as a captain in the 7th Cavalry Regiment of the regular army, and fought in the Indian Wars. He remained with the Army until his retirement on December 15, 1875, just a few months before Custer and most of the 7th Cavalry was massacred at the Battle of Little Big Horn. Mr. Thompson died in Tacoma, Washington, on October 6, 1897.