Stephenson was born on July 8, 1769 in Gettysburg, Pennsylvania, British America.

He moved to Kentucky before his father's death in 1804, and then further westward to the Illinois Territory around 1809, becoming sheriff of Randolph County that same year.

A Democratic-Republican[2] and ally of Governor Ninian Edwards, Stephenson was elected for a two-year term as delegate of the Illinois Territory in the United States Congress from 1814 to 1816, after which he became receiver of Public Monies, appointed by Edwards.

Stephenson was a representative to the convention that wrote the first constitution for the State of Illinois in 1818.

[4] Stephenson died on October 10, 1822, and is buried in Edwardsville, Madison County, Illinois.