. >> massey mckinley, william mckinley's great great nephew and grover cleveland's great great grandson. >> i'm tweed roosevelt, theodore roosevelt's great grandson. >> and ulysses grant dietz. i'm the. youngest great great grandchild. >> of ulysses. >> and julia grant. >> if you didn't tell me, i'd have no clue. they belong to a club that you literally have to be born into. the society of presidential descendants. and every year on presidents day, this fraternity links up in key west, florida, at a historic spot called the little white house for a reunion of first families. so much of america's history is part of their family history. >> susan ford, i think, was said, i wasn't sure, but that the job was sort of twofold, one to, you know, keep up with the legacy, your ancestors legacy, to preserve that, promote it and defend it. but the second part of the job is to do something with it on your own, make it your own in some way. >> part of the preservation is sharing stories with eager audiences. at harry truman's second home, the little white house is a museum now, but clifton used to c