BLACKBURN, JOSEPH (c. i7oo--176o), American por trait-painter, probably came from England, landing in New York and going almost immediately to Boston, where most of his work was done. It was not until 192o that his Christian name was defi nitely known. No record of his birthplace or antecedents has been found ; nor is there any knowledge of his connections in America or where and when he died. For many years he has been called Jonathan B., all his paintings being signed "J" or "I." His patrons came mainly from important early American families, including the Apthorps, Bowdoins, Bethunes, Bulfinches, Ervings, Faneuils, Phillips and Winslows of Boston; the Atkinsons, Cutts, Warners and Wentworths of Portsmouth; and the Bours and Brown fam ilies of Newport. His work, in treatment and method of painting costume, resembles that of Thomas Hudson, who may have been his master, and to some extent that of Joseph Highmore. It is inferior to the work of Robert Feke, his contemporary, but he surpasses Smybert in decorative quality and truthful drawing. Blackburn's influence was felt by Copley, then in his formative period; and until recently much of his work has been attributed to Copley. More than 8o portraits by him are now known to exist, most of them owned by private individuals; the remainder scattered among museums of art, colleges and historical institutes. Two are in the Metropolitan Museum in New York city; others in the art museums of Cleveland, Worcester, Boston and Brooklyn.