Yes, Robert E. Lee was related to Martha Washington through marriage. Robert E. Lee’s mother, Ann Hill Carter, was a descendant of the same family as Martha Washington, who was born Martha Custis. This means that Robert E. Lee and Martha Washington were distant relatives, as they both descended from the Carter family lineage in Virginia.
This connection highlights the intertwining of prominent Virginian families during that era, reflecting the social networks that existed among the early American elite. Although the relationship between them is not particularly close, it bears significance in understanding the familial ties that connected many figures in early American history.