Knox's Headquarters State Historic Site, in the town of New Windsor in Orange County, New York, consists of the Georgian house of the Ellison family, built in 1754 by immigrant William Bull[3][4] of Hamptonburgh, NY, and the grounds around it.

The site is located on Old Forge Hill Road, just south of Route 94 east of Vails Gate.

The book is illustrated with McNeil's own photographs (made circa 1911 or 1912) of the various buildings and bridge at the Knox site.

The Jane Colden Plant Sanctuary along some of the trails in the nearby woods memorializes America's first female botanist, who also resided in the area.

Media related to Knox's Headquarters State Historic Site at Wikimedia Commons