He is a member of the NYC Pastel Society of America, and has received the Connecticut Pastel Society Award in 1997 and the George Innes Jr. Memorial Award for a Pastel at the Salmagundi Club Show in NYC in July 1996.
His work can be found in the El Prado Gallery in Sedona, Arizona; the E.S. Lawrence Gallery in Aspen, Colorado; Gallery 209 in Dallas, Texas; and Saks Galleries in Denver, Colorado.
O'Hagan has exhibited extensively both domestically and internationally, and his work has appeared in numerous publications, including Artists of America, Southwest Art Magazine, Best of Oil Painting, Best of Pastel, Hemispheres Magazine, The Denver Post, and many more.