May 29

Animators working for Walt Disney begin what was to become a successful 5-week strike for recognition of their union, the Screen Cartoonists' Guild. The animated feature Dumbowas being created at the time and, according to Wikipedia, a number of strikers are caricatured in the feature as clowns who go to "hit the big boss for a raise" - 1941
 
A contract between the United Mine Workers and the U.S. government establishes one of the nation's first union medical and pension plans, the multi-employer UMWA Welfare and Retirement Fund - 1946
 
The United Farm Workers of America reaches agreement with Bruce Church Inc. on a contract for 450 lettuce harvesters, ending a 17-year-long boycott. The pact raised wages, provided company-paid health benefits to workers and their families, created a seniority system to deal with seasonal layoffs and recalls, and established a pesticide monitoring system – 1996

UAW members at General Motors accept major contract concessions in return for 17.5 percent stake in the financially struggling company - 2009