As of March 2016, the largest earthquake to shake the United States was a magnitude-9.2 temblor that struck Prince William Sound, Alaska, on Good Friday, March 28, 1964. (Photos shows the Four Seasons Apartments in Anchorage, a six-story lift-slab reinforced concrete building, which cracked to the ground during the quake.) And the world's largest earthquake was a magnitude 9.5 in Chile on May 22, 1960, according to the U.S. Geological Survey (USGS).
