This is a set of maps from the US Army Engineer Water Resources Support Center. Published in 1981, these maps provide info on commodity shipping at US ports. The maps are very clean and crisp, they would look good on the wall. The intro mentions a map number 20, which I did not find. Maps are 19 inches X 28 inches.There are 19 maps on 16 sheets. The paper case which hold the m maps is frayed, creased, and has a small tear or two, but the maps are very nice