Discovering a relationship to Robert E. Lee to or any other historical personage can be done by researching records establishing a line of descent or kinship. Because Lee was a famous man and a member of a prominent family, finding records related to his children and family is relatively easy.
Genealogical research usually begins with the gathering of family records. Birth certificates, newspaper clippings, personal letters, official records kept by counties and parishes, entries in family Bibles and family stories can all yield valuable clues. From these pieces of information, amateur and professional genealogists work backwards to examine and evaluate records for historical information about ancestors. Several onine genealogical databases and forums can help a researcher trace his ancestry.