Attributed to Jeremy Belknap, the manuscript map of Plymouth Harbor shows the coast of Massachusetts from Marshfield to Eel River (now Beach Park), including Duxborough (now Duxbury), Clarke's Island, Sauquish Point (now Standish Point), and Gurnet Lighthouse. The map also shows the locations of roads from Boston to Plymouth, as well as roads from Plymouth to Sandwich, Taunton, and to Manimet Parish (now Manomet).

Three numbers on the map indicate the following:
"1. The place where the first settlers landed on 22 Dec'r 1620. N.S." [New Style date]
"2. The brook on the N side whereof they halted for the first winter."
"3. Clarke's I. where they spent their first Sabbath after their arrival on the coast on 8 Dec'r. 1620. O.S." [Old Style date]