For decades, a mysterious 19th-century portrait of a young boy and his dog hung in the Virginia governor's mansion. The sitter and artist were unknown.

Earlier this year, antiques dealer Alexander Reeves mentioned on a private tour of the mansion that the painting resembled the work of well-known American artist George Caleb Bingham (1811-1879), who had roots in Virginia and is known for his frontier images of Missouri.

Research revealed that the boy sitter was Colin Dunlop, a Virginian who was killed in the Civil War in 1864.

Fred R. Kline, director and editor of the George Caleb Bingham Catalogue Raisonne Supplement Ltd. in Santa Fe, N.M., confirmed the attribution to Bingham. He believes the work was painted in 1841, when the artist was in Petersburg, Virginia, for six months.

"This is a delightful, memorable, and endearing portrait of a boy and his dog, Bingham's first in this rare genre for him," said Tom Camden, director for special collections and acting state art curator for the Library of Virginia.