Albert G.A. Harnickell was Captain of Company F of the 84th New York Volunteer Infantry Regiment (commonly known as the 14th Regiment of the New York State Militia, or the "Fighting 14th") during the Civil War. After the War he was one of several members of the 84th Regiment who reenlisted for service in the New York State National Guard, and he was also active in the 84th Regiment Veterans' Society. He later became a broker in New York City. Harnickell and his wife, Francesca S. Harnickell, had at least one son, Henri Conrad Harnickell.
From the guide to the Albert G.A. Harnickell papers, Bulk, 1861-1887, 1861-1918, (Brooklyn Historical Society)