Griffin was admitted to the bar in May 1858 and in November moved to Grand Rapids, where he begin to practice in the office of prominent Western Michigan lawyer Lucius Patterson.

Griffin was commissioned by Governor Austin Blair, as Supernumerary Second Lieutenant in Company C of the Fourth Michigan Cavalry, and was mustered into service on August 13, 1862.

On February 24, 1864, he was commissioned as Captain, and on September 15 was assigned as Acting Assistant Adjutant General of the Second Cavalry Division.

In 1890, when Berry retired and Hunt was elected assistant prosecuting attorney for Detroit, the firm's name returned to "Griffin & Warner".

In November 1893, Griffin was elected a Democrat from Michigan's 1st congressional district to the 53rd Congress to fill the vacancy caused by the death of John Logan Chipman, serving from December 4, 1893, to March 3, 1895.