In response to McMahon's expansion, the AWA forged an alliance with several NWA promoters, including Jim Crockett Promotions, Mid-South Wrestling, Pacific Northwest Wrestling, World Class Championship Wrestling, and the Continental Wrestling Association. This new promotion was known as Pro Wrestling USA and came about in an attempt to establish a national presence to compete against the WWF. The AWA was also able to sign top wrestlers like Sgt. Slaughter and Bob Backlund. By 1985, however, the AWA began to lose audiences, as the WWF was gaining wrestling superiority due to the success of WrestleMania I. Later in the year, as this struggle against the WWF progressed, Karbo also sold all his stock to Gagne as well. In September 1985, Pro Wrestling USA would respond to McMahon's rising success by promoting the first "SuperClash". Despite this success, the Pro Wrestling USA collaboration did not last, as Gagne accused David Crockett of trying to sign away AWA talent over to the NWA backstage at numerous Pro Wrestling USA shows.