John Parke Custis (1754-1781)
"Jacky" Parke Custis, of Abingdon Plantation, Fairfax County, Virginia
He was the stepson of George Washington, 1st President of the United States. But, as he predeceased his stepfather, his only son (George Washington Parke Custis) therefore became the President's principal heir. George Custis (Jacky's only son) was the father-in-law of the Confederate General Robert E. Lee.