On June 15, 1864, Arlington National Cemetery was officially established. In the early 1800s, John Parke Custis’ son, George Washington Parke Custis (stepson of President Washington), began constructing a Greek revival mansion on the property as a memorial to the first president. George’s only surviving child, Mary, met and married Robert E. Lee at Arlington. The couple spent the next 30 years traveling between US Army outposts and the mansion, where six of the seven Lee children were born.