Born in Augusta County, Virginia, Harper was in private practice in New Orleans, Louisiana from 1808 to 1829. He also served in the United States Army during the War of 1812 and became a lieutenant colonel. He was a member of the Louisiana House of Representatives in 1814, and was a registrar in the land office of the Eastern District of Louisiana from 1821 to 1824. In 1825, he was a clerk for the United States District Court for the Eastern District of Louisiana, and a city councilman of New Orleans.[1]