Robert Erskine ran the Forges & Manor of Ringwood for nine years during the Revolutionary War. Erskine was George Washington's mapmaker and a notable figure. When he died of pnumonia in 1780, his wife remarried and ran the property. Erskine's grave is on the grounds of Ringwood Manor. 

The London syndicate . . . took several years to secure a suitable manager for their American interests. Finally Robert Erskine was selected for the place, and given ample opportunity to study the English iron industry before his departure for America. Erskine was at that time a well known engineer and inventor. He arrived in New York in the autumn of 1771, and at once assumed the management of the Ringwood property, which he found in poor condition. Struggling for two years, with no help from the owners, he finally offered the property for sale, but finding no buyers, he was obligated to rely on his own efforts. He secured some loans from bankers in New York, which were later all repaid. The property was just getting into successful running shape and making money, when the Revolution began.

As soon as war was declared, Erskine took the side of the Colonists, raising the first Company of soldiers in Northern New Jersey, and equipping them at his own expense. He was soon commissioned Captain by the Continental Congress, and instructed to keep his Company at Ringwood in order to protect the iron works and the army stores collected thee. In anticipation of war he had secured a large supply of powder, which at that time was almost unprocurable. No military raids ever came nearer to Ringwood than those in the Ramapo Valley below Suffern.

Washington, requiring a good surveyor and geographer for his staff work, heard of Robert Erskine, and after interviewing him asked to have him commissioned by the Continental Congress as Geographer and Surveyor General. Erskine served in this capacity until his untimely death in 1780. He supervised the making of over two hundred maps for the Army, and fifty-five of his own drawings are still extant. One particularly fine specimen is now in the J.P. Morgan Library, with annotations in Washington's own handwriting. The New York Historical Society has a large number.

It is because of Erskine's early death, probably from pneumonia, in 1780, that he is not well known in history as one of Washington's trusted officers. George Washington attended Erskine's funeral at Ringwood, which took place the same day Andre was shot. He came to Ringwood from Newburgh. It is said that he planted the oak tree which used to stand beside the grave until it was killed by lightning, but this can scarcely be so, because a tree of that great size must have been at least 250 years old when I was a boy. My father believed that Washington paid for the tomb, but I have found no definite evidence of this.

After Erskine's death the property was managed by Mrs. Erskine, under orders from Congress, which held the property for the British owners. She married Robert Lettice Hooper a year after Erskine's death, and they together operated the property. Their conduct of the business was unsuccessful, as would be expected, and it was sold in 1807 to Martin John Ryerson, who then had iron works at Pompton Lakes nearby.

Revolutionary Patriot. Captain, New Jersey Continental Line, Revolutionary War. Geographer and Surveyor General, Continental Army, who prepared some 130 military maps now preserved in The New York Historical Society collection.

Lodge: not known, but presumed to be at London, England. He attended the celebrated Festival of the Feast of St. John at Morristown, 1779.
Residence: Ringwood