From the US Airways website:
In August, 1985, Piedmont Airlines offered to buy Empire for $40 million. With no route duplication between the two carriers and Piedmont’s desire to pick up a significant amount of Northeast routes, it was the perfect marriage for the two companies. In addition, Piedmont, like Empire, was aggressively buying Fokker F-28-1000s and F-28-4000s aircraft from all over the world. In January 1986, Empire shareholders overwhelmingly voted in favor of the merger.
On May 1, 1986, Empire Airlines became Piedmont, less than three years before Piedmont would become part of US Air.