Born on June 25, 1846, in Dedham, Massachusetts,[1] Colt attended the public schools and Williston Seminary.

[1] Colt was nominated by President James A. Garfield on March 9, 1881, to a seat on the United States District Court for the District of Rhode Island vacated by Judge John Power Knowles.

[1] He was confirmed by the United States Senate on March 21, 1881, and received his commission the same day.

[1] Colt was assigned by operation of law to additional and concurrent service on the United States Court of Appeals for the First Circuit on June 16, 1891, to a new seat authorized by 26 Stat.

[2] He was Chairman of the Committee on Conservation of Natural Resources for the 65th United States Congress and Chairman of the Committee on Immigration for the 66th through 68th United States Congresses.