Ancestry/Genealogy

A large number of people who can trace at least one line back to early colonial days are also related to many of the same royals, and almost all of the royal families of Europe were related. The Europeans in the early days of the American colony were kind of inbred.

Basically, if you find you're related to one of them, you probably related to all of them somehow. It's still fun to trace it back. Geni.com and Ancestry both let you refer to other people's research (if they made it public), so you don't usually have to do all the work yourself. And it can mostly be done on the computer nowadays, instead of trudging around cemeteries, looking for old headstones, lol.