It is estimated that more than 10 million people live in the 26 states east of the Mississippi and the District of Columbia .
As of July 1 , 2007 , the estimated population of the 26 states east of the Mississippi ( not including the small portions of Minnesota and Louisiana that are east of the river ) plus the District of Columbia totals 171,222,291 out of 305,986,357 in the whole nation ( including Puerto Rico and insular areas in the US but not in the East ) , or 55.95 % of the U.S. population .