The Sentry Box (ca. 1786) is an elegant specimen of late-Georgian-style architecture. Brig. Gen. George Weedon of the Continental Army, later mayor of Fredericksburg, built the house and named it to reflect his military career. Weedon's wife, Catherine, invited the family of Gen. Hugh Mercer, who died at the Battle of Princeton, to live with them. The Mercer children later inherited the property and Confederate General Hugh Weedon Mercer was born here. In December 1862, the Union army built its middle pontoon crossing over the Rappahannock River just below the Sentry Box. Intense fighting occurred here, and the house was heavily damaged.