March 31, 1927: Birth of Cesar Chavez.
March 31, 1941: Wisconsin state troopers attack striking auto workers in Milwaukee. The strikers succeed in holding off scabs.
March 31, 1949 – Last great strike of the Canadian Seaman's Union.
March 31, 1966: Two day boycott of Seattle schools protesting de facto segregation.
(Sources: Daily Bleed, and Workaday Minnesota).
