Miller captured the giant slalom to also become the first American ever to claim three medals at the same championships.
Although Miller was expected to be one of the dominant figures at this competition, the overall American effort has been a huge surprise.
The United States won only one medal two years ago at St. Anton and four years ago on home snow at Vail, Col., the Americans were shut out of the medal race.
With three events to go, the United States has won six medals at these championships, just one shy of the normally dominant Austrian team. Kirsten Clark and Jonna Mendes have added to the medal total with a silver and bronze in the women's super-G.
Hans Knauss of Austria led after the first giant slalom run Wednesday, but Miller came from behind in the second run to post a time of 2:45.93. Knauss was second in 2:45.96.
Schlopy came from 23rd place after one run to grab third in 2:45.97.
It was the first time two American men had shared the podium at a World Championship or Olympics Phil and Steven Mahre won gold and silver in the slalom at the Sarajevo Games in 1984.
"Coming here I knew Bode was capable of podiums in four disciplines," said American Coach Phil McNichol. "But if he had done that and none of the others had skied to their potential, I would have been ecstatic for Bode but also disappointed.
"Today Erik saved me from that and proved that the team is strong. We have stepped forward in how we do our work together and that has perpetuated much of the success we've had.
"I wouldn't have said it was a failure if only Bode had won here because ski racing is like roulette. But to reconfirm and give the guys the belief in the team one of the other boys needed to come forward."
"For me to have a fellow American come in third makes it an extraordinary day as this was my dream at the start of the season," said Miller, who also won the combined on Thursday and finished second in the super-G on the opening day of the championships.