Just a couple weeks ago I made the discovery that my family descends from William Brewster (1566-1643), who immigrated to America on the Mayflower in 1620. Technically it's my wife's side that descends from him, so I guess I'm a Mayflower descendant-in-law. My kids would still count though. And for my kids, William Brewster would be their 12th Great Grandfather.
According to a grave marker put up by the William Brewster Society, he was patriarch of the Pilgrims, and their ruling elder from 1609-1644. He was the founder of the Plymouth Plantation and helped establish civil and religious freedom in the new world.
On a side note, another branch of my wife's family (the Coggeshalls) came to the new world and ended up in Boston the 1630's. The Coggeshalls were later exiled, and they ended up going to Rhode Island where there was true religious freedom for everyone. John Coggeshall became one of the eighteen original proprietors of Aquidneck, who settled Pocasset (later Portsmouth), 1638. One of the nine who settled Newport, 1639 and President of the Colony, May 1647 to May 1648. So even though the Massachusetts Colony had religious freedom, it still wasn't totally free which helped spawn the Providence Plantation and Rhode Island. So members of my family were involved in the founding of both Massachusetts and Rhode Island. I think it's pretty interesting history, and have learned a lot researching these families.
I think it's pretty cool that a relative of mine was at that Thanksgiving in 1621, and today in 2011 - 390 years later - we are celebrating Thanksgiving day today with other Mayflower descendants.