Thomas Sully 1831 John Neagle Neagles relationship with Sully was both professional, as the younger artist spent a good deal of time absorbing the older portraitists advice on stylistic and technical matters, and personal, as Neagle married Sullys niece and stepdaughter, Mary Chester Sully, in 1820. The artists portrait sketch of his father-in-law, taken from life on February 17, 1831, evinces a robust delight in making a quick study. Sully is portrayed in his studio, with palette and a fistful of brushes, holding his maulstick. A portrait in progress leans against an easel to his right, and he rests his left hand on another, freshly stretched, canvas.. Thomas Sully. John Neagle (1796-1865). American. 1831. Graphite on off-white wove paper