DUFF, John, actor, born in Dublin, Ireland, in 1787 ; died in Philadelphia, Pennsylvania, in April 1831. Before coming to the United States He was prominent as an actor at the Theatre Royal in his native City. He made his first appearance in this country at the Federal Street theatre, Boston, 8 November 1810, as George Gossamer in "Laugh when You Can." His first appearance in New York was at the Park theatre, 14 January 1814, as Octavian in " The Mountaineers," and the "Three Singles." Mr. Duff was for many years the most popular actor in the old Philadelphia Company, where he was engaged in 1811 as a "stock star," and attracted far better houses than many who claimed the highest honors. His versatility seems to have been unbounded. He could act Richard or Jeremy Diddler, sing a comic song or take a part in an opera, with equal acceptability. In 1823, when he introduced Mrs. Duff to the New York public, the brilliancy of her acting scarcely allowed a thought of him, and soon afterward he suffered greatly from violent attacks of gout ; yet he frequently played at the old Chatham, Bowery, and Lafayette theatres, where he appeared for the last time.

His wife, Mary Ann, actress, born in London, England, in 1795; died in New York, 5 September 1857, was the daughter of an Englishman named Dyke, who had held an office in the service of the East India company, and died, leaving her and her sisters with small support. They received instruction in dancing from the balletmaster D'Egville, and made their first appearance as professional dancers at the Dublin theatre. While playing with a party of amateurs at Kilkenny, Mary attracted the attention of Thomas Moore, who acted the part, of Robin Roughead in " Fortune's Frolic," but, receiving no encouragement, he transferred his affections to her sister, Elizabeth, whom he soon married. After her marriage Mrs. Duff came to Boston with her husband, in 1810, where she made her first appearance on the American stage as "Juliet," but without success. Subsequently she appeared in characters of minor importance, and also in serious pantomimes. In 1817 she began to develop great ability.

In 1823 she visited New York for the first time, and appeared in the Park theatre as Hermione in the " Distressed Mother," adapted from Racine's "Andromache. This was the character in which her talents were first asserted and in which she first became known. About this time she played leading Shakespearean parts with Edmund Kean, who considered her the equal of the foremost British actresses of that day. She visited England in 1828, and made her first appearance in London as Isabella in the "Fatal Marriage." Her beauty and talent made her a great favorite throughout the United States. While she was traveling from Cincinnati to New Orleans upon the Mississippi River the Asiatic cholera broke out among her fellow passengers. Fearless for her own life, she administered to the sick and dying, and upon her arrival in New Orleans received a vote of thanks from the survivors. She made her last appearance in New Orleans in 1838 for the benefit of the orphan boys' asylum. After the death of Mr. Duff she married Mr. Seevir, a lawyer in that City, and retired from the stage.