Mary Jacobs Memorial Library Share: 64 Washington Street Rocky Hill, NJ 08553 609-924-7073 Visit Website Mary Jacobs Memorial Library is a branch of the Somerset County Library System. Nearby LocationsBagel BistroCulinary Creations Catering & RestaurantONE 53 Is this your listing? Gain access now by logging in here. Interested in listing your Somerset County, NJ business on this website? Click here for more information.