Email Record: United States De Soto Exposition Commission. Message from the President of the United States returning without approval the bill (H. R. 9751), for the creation of the United States De Soto Exposition Commission, to provide for the commemoration of the four hundredth anniversary of the discovery of the Mississippi River by Hernando De Soto, the commemoration of De Soto's visit to the Chickasaw Territory in northern Mississippi, and other points covered by his expedition, and the two hundred and fifth anniversary of the Battle of Ackia, and for other purposes.