Born in New York, New York, on February 20, 1803, Henry Stanbery moved to Ohio in 1814. He graduated from Washington College, in Pennsylvania, in September of 1819, and studied law. He was admitted to the bar in Ohio in May 1824 and to the bar of the Supreme Court of the United States in 1832. In 1846 he was elected the first attorney general of Ohio by the State assembly. President Johnson appointed Stanbery Attorney General of the United States on July 23, 1866. He resigned on March 12, 1868, to defend President Johnson during his impeachment trial. At the conclusion of the trial, Johnson renominated him Attorney General and also to the Supreme Court, but the Senate did not confirm him. He died in New York City on June 26, 1881.
The artist was born in New Haven, Connecticut, and learned to paint in his youth. He was a painter of portraits and religious themes. Flagg studied theology and was ordained in the Episcopal Church in 1855.
After 1863 he resumed his career as a professional painter in New Haven and New York City. Flagg died in the latter city. His portrait of Attorney General Stanbery was painted in 1869.