He commenced practice in the Ninety-Sixth District of South Carolina, moving back to Charleston in 1789. From 1790 to 1795, Harper was a member of the South Carolina House of Representatives, at which time he was elected from South Carolina to the Third Congress to fill the vacancy caused by the death of Alexander Gillon. He was reelected to the Fourth, Fifth, and Sixth Congresses but was an unsuccessful candidate for reelection in 1800 to the Seventh Congress, serving as a U.S Representative from February 9, 1795 to March 1801. While in Congress, he was the chairman of the Committee on Ways and Means in the Fifth and Sixth Congresses. Harper was one of the managers appointed by the House of Representatives in 1798 to conduct the impeachment proceedings against William Blount.
Political career in Maryland
Harper moved to Baltimore, Maryland, and engaged in the practice of law. He consorted with the men of the mob riots of Baltimore against the British in June 1812. He served in the War of 1812, attaining the rank of major general. He assisted in organizing the Baltimore Exchange Co. in 1815 and was a member of the first board of directors. He then became a member of the Maryland State Senate, and was later elected from Maryland to the United States Senate for the term beginning March 4, 1815, serving from January 1816 until December 1816, when he resigned. He was an unsuccessful Federalist candidate for Vice President in the 1816 election. He also received one electoral vote for Vice President in the 1820 election. In 1815, Harper was elected a member of the American Antiquarian Society. and traveled extensively in Europe in 1819 and 1820. He took a prominent part in the ceremonies on the occasion of Lafayette’s visit to Baltimore in 1824.
Personal life
On May 7, 1800, Harper married Catherine Carroll in Anne Arundel County, Maryland. Catherine was the daughter of Charles Carroll and Mary Carroll. Her elder sister, Mary, married Richard Caton. Together, they were the parents of at least four children who survived to adulthood, including:
Charles Carroll Harper, who married Charlotte Hutchinson Cheffelle in 1827.
Mary Diana Harper, who died young.
Richard Caton Harper, who died young.
Elizabeth Hyde Harper, who died unmarried.
Emily Louisa Harper, who never married.
Robert Goodloe Harper, Jr.
He died in Baltimore on January 14, 1825, and was initially interred in the family burial ground on his estate, Oakland in Roland Park, and later reburied in Greenmount Cemetery in Baltimore.
Descendants
Through his eldest son Charles, he was a grandfather of Emily Louisa Harper, who married William Clapham Pennington. Their son, Robert Goodloe Harper Pennington was a prominent artist.
