Location of Bartram's house and garden in relation to the (freshwater) tidal marshes at the confluence of the lower Schuylkill River (thin waterway, upper right of image) and the Delaware River (wide waterway, bottom of image). This map showing “early settlements of Delaware County, Penna.” as they appeared in 1790, was published in 1862 by G. Smith and H. B. Ashmead, Bowen & Co., Philadelphia. It has been modified to highlight the extent of the marshes (dark gray) that were one of Wilson's favorite collecting grounds.