April 14
April 14, 1894 - American Railway Union President Eugene V. Debs spoke to a mass meeting at Labor Hall in downtown St. Paul. In his remarks and speeches later that week, Debs urged solidarity among all workers and rallied support for the workers on strike against the Great Northern railroad.
More than 100 Mexican and Filipino farm workers are arrested for union activities, Imperial Valley, Calif. Eight were convicted of “criminal syndicalism” - 1930
John Steinbeck’s “The Grapes of Wrath” published - 1939
And this:

April 14, 1939 - John Steinbeck’s “The Grapes of Wrath” was published. The novel of social protest dramatized the story of “Okies” – workers who migrated from Oklahoma’s dust bowl to the groves of California – and experienced tremendous hardships and exploitation along the way.
The United Steelworkers and the Paper, Allied-Industrial, Chemical and Energy Workers unions merge to form the largest industrial union in North America - 2005
Labor history found here:
http://www.unionist.com/today-in-labor-history & here:
http://www.workdayminnesota.org/index.php?history_9_04_14_2011