Legend has it that when the Pilgrims arrived in the new world aboard the "Mayflower", they disembarked on a boulder that became known as Plymouth Rock. History states that a churchman named Thomas Faunce identified this rock in 1791 from memory, afterwhich it was moved several times.
For the upcoming asteroid next decade, we could name the ARV spacecraft going to the asteroid belt the "Thomas Faunce Labratory" and the asteroid "Plymouth Rock", making it the equivalent monument in space. Then in the mid 2020s, Pilgrimnauts aboard the spacecraft "Mayflower" could go investigate the asteroid Plymouth Rock in lunar orbit. When they get there, they can mount a plaque made from the original boulder on the asteroid, symbolizing both America's expansion into deep space, as well as all humanity.