His life and career were among several prominent officers profiled by author Theo F. Rodenbough in his books Uncle Sam's Medal of Honor (1886) and Sabre and Bayonet: Stories of Heroism and Military Adventure (1897).

Born in Athlone, Ireland in 1827, James Fegan served some time with the Irish Constabulary prior to emigrating to the United States in 1850.

As part of the Army of the Potomac, he saw action at Gaines' Mill, Malvern Hill, Hanover Court House, Fair Oaks, Harrison's Landing, Bull Run, Centreville, South Mountain and Antietam.

Camping one night near Plum Creek, however, Fegan was confronted by a fellow soldier, Sergeant John W. Blake of the 7th U.S. Cavalry, who had organized a posse from local townspeople and demanded that the deserter be released.

Fegan ran off the mob single-handed, wounding two of his attackers, and continued to Fort Dodge where he safely arrived on March 13.

His life and career was profiled by author Theo F. Rodenbough in his books Uncle Sam's Medal of Honor (1886) and Sabre and Bayonet: Stories of Heroism and Military Adventure (1897).

His son, John Fegan, Jr., had joined the 3rd Infantry and eventually became a sergeant alongside his father in Company H. He retired from active service at Fort Missoula in the Montana Territory on May 8, 1885.