Van Buren was born in 1782 so he was qualified to be president for the same reason Washington and Jefferson and Jackson were - citizen of the U.S. at the time the Constitution was ratified.
And he was a natural born citizen of the United States. He was doubly eligible you might say.
53 posted on 05/07/2010 8:34:34 PM PDT by El Gato
("The second amendment is the reset button of the US constitution"-Doug McKay)