In 1836 he crossed the Atlantic and first appeared as Spartacus in Drury Lane Theater, London, October 17. He achieved distinguished success, and acquired the friendship of Macready, Kemble, and others.
In 1837 he married Catherine Norton Sinclair, daughter of John Sinclair the singer, and soon afterward returned to the United States, where he was welcomed by enthusiastic audiences.
In 1845 Mr. and Mrs. Forrest returned to London. During this visit, which lasted two years, a rupture occurred in the friendly relations between Forrest and Macready, and to the zeal with which the friends of the former espoused his quarrel was due the disgraceful riot in New York, May 10, 1849, during an engagement of Macready at the Astor Place Theater. This was accompanied by serious loss of life.
Soon after Forrest separated from his wife, and between 1853 and 1860 he retired from professional life, but when he returned to the stage he filled the role of Hamlet with all his former acceptance.
Latterly he suffered considerably from illness, and his last engagement began on February 6, 1871.
He died of apoplexy, surviving the attack only half an hour.
He was a man of fine presence, well equipped for his profession, naturally frank and engaging.
A large part of his valuable library and Shakespeare collection, which he had spent many years in gathering, was almost entirely destroyed by fire in his house in Philadelphia, January 15, 1873.