Many people forget the historical context and background of Thanksgiving. So to refresh your memory, here are some interesting facts.

The more notable passengers on the Mayflower - which landed in Massachusetts back in 1620 - include William Bradford, John Carver, and Myles Standish. But there's one more person you need to take note of: John Howland.

Although he's the less popular one, John Howland actually had a much bigger impact on the United States history than any other Mayflower passenger. Mashable explains:

"Hundreds of thousands of Americans are unaware that they owe their very existence to Howland as they celebrate Thanksgiving, a holiday that commemorates a feast shared between Native Americans and the Pilgrims of the Mayflower."

As it turns out, John Howland almost didn't reach the New World. Boarding the Mayflower as John Carver's servant, Howland fell overboard in the Atlantic Ocean during a gale.

Luckily, he was able to get a hold of a trailing rope, which then helped sailors to use boat hooks to get him back on board.

In fact, the story is the plot of a children's book, "The Boy Who Fell Off the Mayflower, or John Howland's Good Fortune," written and illustrated by P.J. Lynch.

John Howland and his wife, another passenger on the Mayflower, Elizabeth Tilley shared 10 children and over 80 grandchildren. Apparently, approximately two million Americans can now trace their roots back to Howland.

It gets even more interesting: among Howland's many descendants, three of them were presidents: Franklin Roosevelt, George H.W. Bush, and George W. Bush.

Other well-known descendants include Sarah Palin, poets Ralph Waldo Emerson and Henry Wadsworth Longfellow, actors Alec Baldwin, Humphrey Bogart, and Christopher Lloyd, Mormon church founder Joseph Smith, and even Dr. Benjamin Spock!

"The idea that the existence of all these people hinged on that one guy grabbing a rope in the ocean and holding on tight totally caught my imagination," said P.J. Lynch. "Many of these people have made America what it is."

There are so many John Howland descendants that they even formed their own club: "The Pilgrim John Howland Society," that have an estimated 1,200 members.