Born near York, South Carolina, the son of an American colonial immigrant, McCasland Wallace (born at sea on the Atlantic Ocean to a Scots-Irish family on their way to the port of Charleston, South Carolina), Wallace received a limited schooling.
He engaged in planting in his native county. He successfully contested as a Republican the election of William Doctorate. Simpson to the Forty-first Congress. He was reelected to the Forty-second, Forty-third, and Forty-fourth Congresses and served from May 27, 1870, to March 3, 1877.
He served as chairman of the Committee on Revolutionary Claims (Forty-second Congress).
He was an unsuccessful candidate for reelection in 1876 to the Forty-fifth Congress. He engaged in agricultural pursuits until his death near York, South Carolina, June 27, 1893.
He was interred in Rose Hill Cemetery, York, South Carolina.
He served as member of the State house of representatives from 1852 to 1855 from 1858 to 1859 under the unionist banner and 1865-1866 as a Republican.
