[1] He was the eldest son of Joel Barlow Sutherland of Philadelphia, who had been a militia officer in the War of 1812 and served as a Member of Congress when Thomas was a child.
He followed a river route from the Saint Anthony Falls to the location that would later become Madison, Wisconsin, which at the time was still inhabited only by the Ho-Chunk.
[1] He was admitted to the Pennsylvania Bar Association in 1839 and formed a legal partnership in Wisconsin with David Brigham with the endorsement of his father and several other notable politicians.
That same year, he was appointed United States Attorney for the Wisconsin Territory by President John Tyler and remained in that role until the inauguration of James K. Polk in 1845.
Sutherland was appointed to the Board of Regents by Governor Nelson Dewey, along with other early Wisconsin dwellers Edward V. Whiton, Alexander L. Collins, John H. Rountree, and Rufus King.