He was an important staff officer under George B. McClellan during the 1862 Peninsula Campaign, serving as the Provost Marshal of the Army of the Potomac.

He was the son of Sarah Humes and George Bryan Porter (1791–1834), a governor of the Michigan Territory.

He was a grandson of Revolutionary War officer Andrew Porter and a second cousin of Mary Todd Lincoln.

Within a year, he was promoted to captain and cited for gallantry, being brevetted two grades to lieutenant colonel.

However, he died at his home there in 1872, and his remains were returned to the United States for burial in Elmwood Cemetery in Detroit.