Robert E. Lee (Robert Edward Lee, 1807–1870), the Confederate general.
George Washington Custis Lee (1832–1913) — often called "Custis Lee" — was the eldest son of Robert E. Lee and Mary Anna Randolph Custis Lee, great-granddaughter of Martha Washington and only surviving child of George Washington Parke Custis, builder of Arlington House. The name honors the boy's maternal grandfather, George Washington Parke Custis, whose own name honored George Washington, who had raised "Wash" Custis as an adopted son after the death of Martha's son John Parke Custis in 1781 [blogspot].
Custis Lee graduated first in his West Point class of 1852, inherited Arlington House after his father's 1870 death, served as a Confederate general, and later became president of Washington and Lee University (renamed in his father's honor shortly after his death). He also arranged the 1882 sale of the Arlington estate to the U.S. government, on the condition that the graves of Union dead there be preserved — what became Arlington National Cemetery.
His siblings were William Henry Fitzhugh Lee ("Rooney") and two daughters who died young, Mary and Annie [blogspot].