December 7
Heywood Broun born in New York City. Journalist, columnist and co-founder, in 1933, of The Newspaper Guild - 1888
And this:

December 7, 1888 - Heywood Broun was born in New York City. A journalist and columnist, he co-founded The Newspaper Guild and recruited several high-profile members, including First Lady Eleanor Roosevelt. "Small fry are no longer small when they begin to organize," he said. "They take on purpose and power."
Steam boiler operators from 11 cities across the country meet in Chicago to form the National Union of Steam Engineers of America, the forerunner to the International Union of Operating Engineers. Each of the men represented a local union of 40 members or fewer - 1896
More than 1,600 protesters staged a national hunger march on Washington, D.C. to present demands for unemployment insurance - 1931
December 7, 1941 - Pearl Harbor was attacked, sparking U.S. entry into World War II. Millions of American working people, from soldiers to "Rosie the Riveter," sacrificed for their country.
United Hatters, Cap & Millinery Workers International Union merges into Amalgamated Clothing & Textile Workers Union - 1982

Delegates to the founding convention of the National Nurses United (NNU) in Phoenix, Ariz. unanimously endorse the creation of the largest union and professional organization of registered nurses in U.S. history. The 150,000-member union is the product of merger of three groups - 2009
Labor history found here:
http://www.unionist.com/today-in-labor-history & here:
http://www.workdayminnesota.org/index.php?history_9_12_07_2010