George Michael Decker Hahn, was an attorney, politician, publisher and planter in New Orleans, Louisiana. He served twice in Congress during two widely separated periods, elected first as a Unionist to the U.S. House of Representatives in 1862, as a Republican to the U.S. Senate in 1865, and later as a Republican to the U.S. House of Representatives in 1884. He was elected as the 19th Governor of Louisiana, serving from 1864 to 1865 during the American Civil War, when the state was occupied by Union troops. He was the first German-born governor in the United States, and is also claimed as the first ethnic Jewish governor. By that time, he was a practicing Episcopalian.

The Unionist Party, later known as the Unconditional Union Party in the border states, was a political party in the United States started after the Compromise of 1850 to define politicians who supported the Compromise. It was used primarily as a label by politicians who did not want to affiliate with the Republicans, or wished to win over anti-secession Democrats. Members included Southern Democrats who were loyal to the Union as well as elements of the old Whig Party and other factions opposed to a separate Southern Confederacy.