Timothy O'Sullivan

(c. 1840 – January 14, 1882)
Was a photographer prominent for his work on subjects in the American Civil War and the Western United States. O'Sullivan was born in New York City. As a teenager, he was employed by Mathew Brady. When the Civil War began in early 1861, he was commissioned a first lieutenant in the Union Army and, over the next year, fought in Beaufort, Port Royal, Fort Walker, and Fort Pulaski. {Via Wikipedia}