David Kunst was a restless 30-year-old with dreams in 1970. We don't know all the factors that went into his decision to walk around the world, but it was a big, brash project that appealed to him, and to his brothers. Now, the world is mostly ocean, and David didn't walk across those, but crossed continent after continent on foot. He and his younger brother John secured a financial sponsor and letters of introduction from Minnesota senators Hubert Humphrey and Walter Mondale. They had a wagon of supplies pulled by a mule, or actually several wonderfully-named mules, but only one at time. They walked from Minnesota to the east coast, then from Spain across Eurasia. Despite diplomatic efforts, they couldn't get permission to cross through the Soviet Union or China, so they took more dangerous routes. That led to John's death when he was shot by bandits. But David walked on, with his other brother Pete joining him. In Australia, David met his second wife. He finally made it all the way around the world when he walked back into Minnesota four years after walking out. Read the story of David Kunst's impossible quest at Smithsonian.