He first appeared there aged nine in Boston as Crack in The Turnpike Gate, a play by Thomas Knight, in which he sang a duet with his father "When off in curricle we go".

[1] At the age of 20, he returned to Britain, first to Edinburgh where he became a successful actor working for his uncle W. H. Murray, who managed the Theatre Royal and the Adelphi there.

[1] According to music hall historian Harold Scott, Cowell was "a vividly remembered personality.. [who] ranks.. among the greatest exponents of entertainment.

His health, previously robust, began to break down;[1] his wife's diary described him at one point as "feeble as an infant... merely skin and bone", but he continued to tour in the U.S. and Canada.

Sam Cowell died in the following March and was buried in the cemetery at Blandford Forum, where there is a monument to him erected by his friends.