Born in England, Swanwick and his family arrived in the American colonies in the early 1770s. He engaged in mercantile pursuits in Philadelphia under Robert Morris, and was also interested in literature, having published a volume of poetry. He was elected as a Democratic-Republican to the Fourth and Fifth Congresses and served from March 4, 1795, until his death.
While in the House he was chairman of the Committee on Commerce and Manufactures (Fourth Congress).
Swanwick died on August 1, 1798, in Philadelphia, where he was interred at Saint Peter"s Church.