Sorry, but I got the wrong exposition for Sousa and the VPI band. It was in Buffalo NY in 1901, but it was called The Pan American Exposition. The Columbian Exposition was in 1893 in Chicago.
I have been able to verify that Sousa and his band were there and that part of the VPI cadet corps also was, but so far no independent verification that the VPI band so impressed Sousa, that he dedicated HANDS ACROSS THE SEA to them. I hope somebody is working on this. Its a great story if true.
Randy Cabell