Robert Erskine was a Scottish polymath, inventor, and engineer who ran the Ringwood Ironworks in New Jersey. His abilities gained the interest of the leaders of the American Revolutionary movement and in 1776 he was employed to design a 75-ton underwater cheval-de-frise (blockade chain) that was installed across the Hudson River near West Point to prevent passage of British ships upriver.
In 1777 General George Washington appointed him as Geographer and Surveyor General at the rank of colonel. His detailed maps were some of the first accurate depictions of areas strategically important to the Continental Army. His importance to the Colonists got the attention of the Smith’s “Cowboy” gang, and while Erskine was away from his Ringwood home, the gang gained entry by trickery and looted the place.
The map pictured above is an early draft of a more formal one, but one that would’ve been supplied to Washington for immediate use. North is at the bottom, it shows Earl’s Tavern on the Clove Road.