Watch full movie online. Through the use of a Time Machine, Casper the Friendly Ghost gets transported back in time, In the stone-age, Casper frightens cave-men and women. Robert Fulton's steamboat makes a successful first trip when Casper's ghostly form frightens it into action. Casper assists Paul Revere on his famous ride when Revere's horse, frightened by Casper, ceases to balk and breaks into a gallop. George Washington, crossing the Delaware River, is sped up by Casper's appearance, and Casper becomes a hero by besting the British Redcoats.