From July 8 to August 19, 1966 over 35,000 airline workers across the nation employed by five airlines went on strike. After several years of stilted wage gains as the airline industry invested heavily in jet technology, aircraft mechanics and other ground service workers represented by the International Association of Machinists (IAM) were anxious to share in the substantial profits of 1965. Facing a bargaining impasse between the IAM and the five carriers (United, Northwest, National, Trans World and Eastern) covered in the industry’s first multi-carrier labor contract, a Presidential Emergency Board presented a “compromise” package. In the summer of 1966, IAM members rejected this compromise and walked off the job in the largest strike in airline history. For 43 days during the peak summer travel season, 60 percent of the U.S. commercial airline industry was literally inoperative as 35,000 workers stayed out on strike.