He was educated locally and at age 14 joined the Union Army for the American Civil War.

After the war Parker began law school at Columbian College (now George Washington University), from which he graduated in 1868.

Parker practiced law, and in 1874 he was appointed the federal collector of internal revenue for Colorado Territory.

Parker was a delegate to the territorial constitutional convention which led to South Dakota's statehood in 1885.

He was the grandfather of William H. Parker, who served as Chief of the Los Angeles Police Department from 1950 to 1966.