[27]

U.S. Congress
Engraved portrait print of Harrison at age 27, as a delegate member of the House of Representatives from the Northwest Territory, c. 1800 by Charles Balthazar Julien Févret de Saint-Mémin[28][29]
Harrison had many friends in the eastern aristocracy and quickly gained a reputation among them as a frontier leader. He ran a successful horse-breeding enterprise that won him acclaim throughout the Northwest Territory.[12] Congress had legislated a territorial policy that led to high land costs, a primary concern for settlers in the Territory; Harrison became their champion to lower those prices. The Northwest Territory's population reached a sufficient number to have a congressional delegate in October 1799, and Harrison ran for election.[30] He campaigned to encourage further migration to the territory, which eventually led to statehood.[31]
Harrison defeated Arthur St. Clair Jr. by one vote to become the Northwest Territory's first congressional delegate in 1798 at age 26, and served in the Sixth United States Congress from March 4, 1799, to May 14, 1800.[32][33] He had no authority to vote on legislative bills, but he was permitted to serve on a committee, to submit legislation, and to engage in debate.