Timothy H. O'SullivanO'Sullivan began his photography career as an apprentice in Mathew Brady's Fulton Street gallery in New York City and then moved on to the Washington, D.C., branch managed by Alexander Gardner. In 1861, at the age of twenty-one, O'Sullivan joined Brady's team of Civil War photographers. When Gardner left Brady, O'Sullivan went with him, working for Gardner until the end of the war.