Gorman was born near
Flemingsburg, Kentucky. He was the only child of David and Elizabeth Gorman, both of Irish descent. In 1835, the family moved to
Bloomington, Indiana, where Gorman attended
Indiana University and then established a law practice. In January 1836, he married Martha Stone in Bloomington. By 1837 he began his move into politics, becoming a clerk in the
Indiana State Senate. From 1841 to 1844, he was elected to the
Indiana House of Representatives. In 1845 he returned to Indiana University and completed his law degree. In 1846 he volunteered for the army, enlisted as a private, and went to fight in the
Mexican–American War. He was appointed as a
major in the
3rd Indiana Volunteer Infantry, and led an independent rifle
battalion at the
Battle of Buena Vista, where he was severely wounded. When his term of service expired, he re-enlisted and was appointed
colonel of the
4th Indiana Infantry Regiment. He served in the
capture of Huamantla and in several other campaigns and battles under General
Joseph Lane. In 1848 he was civil and military governor of
Puebla, but soon after he returned to Indiana. He served in the
United States House of Representatives from March 4, 1849, to March 3, 1853, as a representative of that state. Gorman, politically a
Democrat, served as the second Territorial
Governor of Minnesota from May 15, 1853, to April 23, 1857, at the appointment of
President Franklin Pierce. During his time as Governor of Minnesota, he masterminded an unsuccessful plan to move the capital of the territory from
St. Paul to
St. Peter, where he owned land that would have been eminently suitable for use as the new capitol grounds. The plan was sidetracked when legislator
Joe Rolette disappeared with the bill until the last seconds of the legislative session. He spent a number of years practicing law in
St. Paul, Minnesota, and served in the
Minnesota House of Representatives from May 11, 1858, to January 1859. With the
secession of several Southern
slave states, Gorman offered his services to the army. He was appointed
Colonel of the
1st Minnesota Infantry, serving in the
First Battle of Bull Run on July 21, 1861. On September 7, 1861, he was appointed
brigadier general of volunteers and assigned to command a
brigade in the
II Corps in
Army of the Potomac during the
Peninsular Campaign. His troops suffered high casualties during the
Battle of Antietam in an ill-fated attack on
Confederate positions in the West Woods. Later in the year, he was assigned to command the District of Eastern Arkansas. ==Postwar==