September 9

In convention at Topeka, Kansas, delegates create the Brotherhood of Railway Carmen of America. The men who repaired the nation's rail cars were paid 10 or 15 cents an hour, working 12 hours a day, often seven days a week - 1890
(Understanding the Railway Labor Act is incredibly helpful to those seeking to learn more about rail labor history, the mechanics of rail labor law, and how railroads and their multiple unions bargain collectively under the RLA's provisions. It is hugely helpful as well to those familiar with the RLA but seeking a reference work providing greater detail on the law's provisions and how they impact negotiations at the national and local levels.)
More than 1,000 Boston police officers strike after 19 union leaders are fired for organizing activities. Massachusetts Governor Calvin Coolidge announced that none of the strikers would be rehired, mobilized the state police, and recruited an entirely new police force from among unemployed veterans of the Great War (World War I) - 1919
And this: September 9, 1919 - During a wave of strikes that swept the country that year, Boston police walked off the job. The police had affiliated their local organization with the American Federation of Labor, prompting the police commissioner to suspend 19 policemen. The officers then went on strike. While local unionists debated whether to call a general strike in support, Massachusetts Governor Calvin Coolidge moved swiftly. He announced that none of the strikers would be rehired and mobilized the state police. An entirely new police force was recruited from among unemployed veterans of the Great War (now known as World War I).
Sixteen striking Filipino sugar workers on the Hawiian island of Kauai are killed by police; four police died as well. Many of the surviving strikers were jailed, then deported - 1924
Labor history found here:
http://www.unionist.com/big-labor/today-in-labor-history & here:
http://www.workdayminnesota.org/index.php?history_9_09_9_2011