Clark was born into slavery in Halifax County and was the son of Mathew Clark and Chaney Clark. Contemporary public records occasionally expand his name to Mathew or Matthew Clark, and sometimes add a terminal
e to his surname, but he signed his name as Matt Clark, and his name appeared in that form in the official proceedings of the House of Delegates. The name of his owner and the circumstances under which he secured his freedom are not known. By 1870 Clark had married Elizabeth Betts, could both read and write, was a farm laborer, and lived in the Mount Carmel district of Halifax County, near the North Carolina border. On October 6, 1870, he paid $154.12 for thirty-four acres of land located at or near the township of Black Walnut, where on May 22, 1873, he was elected justice of the peace.