Arlington National Cemetery in Arlington County, Virginia, is a military cemetery in the United States of America, established during the American Civil War on the grounds of Arlington House, formerly the estate of the family of Confederate general Robert E. Lee's wife Mary Anna (Custis) Lee, a great grand-daughter of Martha Washington. The cemetery is situated directly across the Potomac River from the Lincoln Memorial in Washington, D.C. It is served by the Arlington Cemetery station on the Blue Line of the Washington Metro system.
In an area of 624 acres (253 ha), veterans and military casualties from each of the nation's wars are interred in the cemetery, ranging from the American Civil War through to the military actions in Afghanistan and Iraq. Pre-Civil War dead were reinterred after 1900.

There are over 400,000 military personnel interred here.