Born in Monticello, Indiana, Hartman attended the public schools and Wabash College in Crawfordsville.

He was appointed Envoy Extraordinary and Minister Plenipotentiary to Ecuador in July 1913 and served until May 14, 1922, when he returned to Bozeman.

He moved to Fort Benton in 1927, having been appointed judge of the twelfth judicial district of Montana on March 3, 1927.

Hartman was elected to the same office in 1928, and served until his death in Great Falls, on August 3, 1929.

This article incorporates public domain material from the Biographical Directory of the United States Congress