Or was Washington really the first president after all? A number of historians hold that a patriot named John Hanson was technically the first chief executive because he was elected President of the United States in Congress Assembled on November 5, 1781, the first of seven such one-year termed presidents. In fact, Hanson even introduced the victorious General Washington to Congress a few weeks later when the Revolutionary War ended.
Washington didn't become president until 1789, following the terms of Presidents Hanson, Boudinot, Mifflin, Lee, Gorham, St. Clair and Griffin. But Hanson and the others got a bad press, according to a story in The Star, December 2, 1975, and Washington, Franklin and others soon stole the spotlight. Historians Arthur G. Horton and Merle Jensen are quoted as Hanson authorities in the article and the story they tell of the first American president is a bit different than we are used to.
A lot of sites talk about seven missing presidents, but actually if you count there must be eight. President Hancock was left out. Here is the correct list given by one of the sites below:
John Hanson (1781-82)
Elias Boudinot (1782-83)
Thomas Mifflin (1783-84)
Richard Henry Lee (1784-85)
John Hancock (1785-86)
Nathan Gorman (1786-87)
Arthur St. Clair (1787-88)
Cyrus Griffin (1788-89)

More here:
http://www.project.nsearch.com/profiles/blogs/the-mysterious-disappearance-of-eight-us-presidents