E.L. Cord, best known as the designer of the Auburn, Cord and Dusenberg automobiles, had started Century Air Lines in March 1931. Because Century didn’t have any air mail contracts to subsidize its operations it had to rely solely on passenger revenue.
To build passenger volume, Cord reduced ticket prices, forcing the company to implement extreme cost-cutting measures. Century slashed pilot salaries from $350/month to $150/month. As their flights landed at Municipal, security guards escorted each pilot into the office to sign a new contract at the lower salary. The pilots all refused.
Century’s chief pilot sought assistance David Behncke, president of the Air Line Pilots Assn. (ALPA) less than a year after the union was formed. Behncke led the pilots on strike with the assistance of the AFL. There was a long and ugly campaign. Both sides made heavy use of radio and newspaper ads as well as appealing to legislative bodies including the U.S. Congress. New York Mayor Fiorello La Guardia became a champion for the ALPA cause.
By late 1932, the tide turned against Cord and he sold Century Air Lines to Aviation Corp. of Delaware (AVCO).
 AvGeekery: Aviation News and Stories by Professional Avgeeks (online);
"Early History of ALPA, the Air Line Pilots Association and the First Airline Strike;" by JP Santiago; accessed 5/10/2017.
Errett Loban Cord: His empire, his motorcars; by Griffith Borgeson;; Automobile Quarterly Publications, 1985; p. 124-129.
Flying the Line: The First Half Century of the Air Line Pilots Association;by George E. Hopkins; Washington D.C.: Air Line Pilots Assn. International; 1982; p. 43-53.
Balloons to Jets: A Century of Aviation in Illinois 1855–1955; by Howard L. Scamehorn; Carbondale IL: Southern Illinois University Press, 2000. p.152.