What president was a spelunker?
This was claimed of our First President, George Washington but appears to be, at this distance in time, one of those posthumous myths- of which many have been done on Washington- and other historical characters. He never threw a Silver dollar across the Potomac- for the simple reason, even if the feat was feasible- there were no American Minted silver dollars until after his death! it would be like Julius Caesar with a Beretta pistol- chronologically impossible.
