Gen. George Washington faced a myriad of obstacles in the summer of 1781. In George Washington at "Head Quarters, Dobbs Ferry," author and historian Mary Sudman Donovan explores this crucial period during the American Revolutionary War by chronicling his activities. In July, he moved a large contingent of the Continental army to the east bank of the Hudson River near the eastern terminus of Dobbs Ferry. There, on a large expanse known as Philipsburg,...