Not knowing who would be popular to Americans, here is Einstein to Madame Chiang Kai-shek
http://www.geni.com/path/Albert-Abraham-Einstein+is+related+to+蔣宋美齡...
Maybe a bit too long, but it does go through three prominent statesmen in late 19th century China.
Mayling Soong is Albert Abraham Einstein, Nobel Prize in Physics, 1921's great grandson's wife's aunt's husband's aunt's husband's first cousin once removed's wife's sister's husband's half sister's husband's sister's husband's first cousin's wife's first cousin twice removed's wife's grandfather's wife!
I think that is the longest relationship description that I have ever seen!!!
Very interesting to me. I would love to see a much closer relationship to a famous person of any other continent. I am sure that they are already out there, but I never see them in the areas that I have worked in. I guess it is because that my relatives are not famous.