John Singleton Copley (1738–1815) is believed to have been born in Boston, where his mother kept a tobacco shop. His stepfather, the engraver and portraitist Peter Pelham, may have given him his first instruction, and he was working as a professional portrait painter before he came of age. He became the leading portraitist of the wealthy in colonial New England, and A Boy with a Flying Squirrel, a portrait of his half-brother Henry Pelham, established his reputation in England when it was exhibited there in 1766.
His family connections were Loyalist, and in 1774 he left Boston for London, never to return. There he continued to paint portraits and, alongside Benjamin West, developed a new kind of history painting with modern subjects in modern dress. Watson and the Shark was his first venture into the genre, and The Death of the Earl of Chatham made his name as a history painter. His later years were less successful, and he died in London heavily in debt.
Here: The Nativity.