Lemuel Abbott was probably born in Leicestershire in about 1761 (though perhaps earlier, between 1755 and 1757), the son of the Reverend Lemuel Abbott. He became a pupil of Francis Hayman in London in 1775, but returned to Leicestershire after Hayman's death the following year. He settled in London in about 1780 and married, probably between 1786 and 1787, a Roman Catholic of whom only the first names--Anna Maria--are known. Abbott exhibited portraits at the Royal Academy of Arts in 1788, 1789, 1798, and 1800. His certain portraits are all of male sitters, many of them naval officers. Ben Marshall, later an accomplished sporting painter, was apprenticed to him for three years in 1791 (but remained only briefly).
In 1798, the year in which he was an unsuccessful candidate for Associateship of the Royal Academy, Abbott became insane, allegedly as a result both of his failure to keep up with his work and because of domestic disquiet. He was certified in 1801. He seems to have been attended by Dr. Thomas Monro, a specialist in insanity and patron of many young artists, whose portrait he exhibited at the Royal Academy in 1800. Abbott died in London on 5 December 1802.
[Hayes, John. British Paintings of the Sixteenth through Nineteenth Centuries. The Collections of the National Gallery of Art Systematic Catalogue. Washington, D.C., 1992: 3.]
Sewter, Albert Charles. "Some New Facts about Lemuel Francis Abbott." The Connoisseur 135 (1955): 178-183.
Hayes, John. British Paintings of the Sixteenth through Nineteenth Centuries. The Collections of the National Gallery of Art Systematic Catalogue. Washington, D.C., 1992: 3.