George Washington, Freemasons

That's right. The first president of the US also happened to be rather involved in a secret society.

That's because George Washington was also the country's first ever Masonic president.

In Ron Chernow's "Washington: A Life," he notes that the future president may have been attracted to the Masonic Order's adherence to Enlightenment ideals.

Washington joined the Order of the Freemasons early in his life, entering Fredericksburg Lodge No. 4 at the age of 20, according to Mount Vernon's official website. Washington had lost his older brother Lawrence to tuberculosis only a few months earlier, effectively becoming head of the household.

Washington stayed in touch with his Masonic brothers for the rest of his life.

Masonic influences came into play at Washington's first inauguration. During the ceremony, he swore his oath on a Bible from St. John's Masonic Lodge No. 1 in New York (the book, as Mental Floss reports, was randomly opened to Genesis 49:13: "Zebulun shall dwell at the haven of the sea; and he shall be for an haven of ships; and his border shall be to Zidon").

The first president's Masonic ties followed him his entire life — and beyond. There's even a George Washington Masonic National Memorial, which was dedicated in 1932 and finally completed in 1970.