Duncan, Sherman & Company was a New York City banking firm. It was established in 1852 by Alexander Duncan, Watts Sherman and William Butler Duncan Sr.. Although he trained as a physician William Watts Sherman followed his father Watts Sherman into the company. It was the banker for the Hansom Cab Company. J.P. Morgan apprenticed at the firm before establishing his own. New York City architect Alexander Saeltzer designed the Duncan, Sherman Company building at 11 Pine Street on the corner of Nassau.