[1] He moved to Idaho Territory in 1881, settling in Hailey, a community in the Wood River mining district, opening the firm of Angel & Sullivan.

[3] Along with Joseph W. Huston and John T. Morgan, Sullivan won election to the Idaho Supreme Court in 1890, when Idaho became the 43rd state and held its first state election.

Sullivan drew a two-year term, and he was appointed the first chief justice of the court.

[4] Sullivan retired from the court in 1917, replaced by John Campbell Rice.

[3] Sullivan died in Boise of a heart attack on January 31, 1938.