Arlington House, the mansion at Arlington National Cemetery, was originally built by George Washington Parke Custis, who was George Washington's adopted grandson. It was built to serve as a monument to his grandfather. Management of the mansion later passed to Confederate General Robert E. Lee, whose wife Mary, Custis' only child, was granted usage of the estate during her lifetime through provisions in her father's will. The property had fallen upon hard times and disrepair when Lee returned from the Mexican American War to oversee the property. However, before the outbreak of the War between the States, Lee had returned the property to good repair and profitability. Arlington House stands atop a crest of Virginia hillside rising above the Potomac River where it overlooks Washington, D.C.
After Virginia ratified secession, Union troops crossed the Potomac and, under Brig. Gen. Irvin McDowell, took up positions around Arlington. During the occupation the Union founded several military installations at and around the mansion. These installations are survived today by parks in the surrounding community as well as Fort Myer.