Who Does Rob Think He Is?

Tonight at 8 p.m. EDT, NBC airs another episode of its popular “Who Do You Think You Are” series … this time starring actor Rob Lowe and the Library of Congress. You can catch a quick preview here.

Lowe ventures into his past and discovers an ancestor who battled against George Washington during the American Revolution.

While I can’t reveal all of the juicy details, I can tell you that Lowe spent a considerable amount of time in the Library’s Manuscript Division mining the Peter Force Collection of Americana, as well as working with our curators in the Local History and Genealogy Division.

“Who Do You Think You Are?” follows some of today’s most beloved and iconic celebrities as they embark on personal journeys of self-discovery to trace their family trees. In addition to Lowe, this season’s celebs include Martin Sheen, Marisa Tomei, Blair Underwood, Helen Hunt, Reba McEntire, Jerome Bettis, Rita Wilson, Edie Falco, Rashida Jones, Jason Sudeikis and Paula Deen.