1. May Day March, 1909 Via jewishlaborcommittee.org These women, marching on May 1, 1909 in New York, wear signs reading "Abolish Child Slavery" in English and Yiddish. Jewish workers in the US began forming unions [pdf] in the 1880s, and the Jewish labor movement experienced a turning point in the 1930s as Jewish workers turned away from Communism and began to respond to growing anti-Semitism worldwide. 2. New York Shirtwaist Strike, 1910 Via cdn.dipity.com Women working in shirtwaist factories went on strike from late 1909 until early 1910. Management eventually met their demands for better wages and working conditions, but the Triangle Shirtwaist Factory fire in 1911 showed that workplace safety standards still had a ways to go. 3. Women in the Puerto Rican Labor Movement, early 20th century Via chnm.gmu.edu Women played an important part in the Puerto Rican labor movement, protesting against forced sterilization and economic inequality. 4. Amalgamated Clothing Workers Strike, 1915 Via jwa.org Women from the Amalgamated Clothing Workers union went on strike in 1915 to protest sweatshop conditions and excessively long workdays. 5. Women's Employment Poster, WWI Via depts.washington.edu While women's factory work during World War II is better-known, women also took factory jobs while men were fighting overseas in World War I. The wage inequality they faced during this time inspired many to join unions. 6. London Protest, 1935 Via kids.britannica.com These women were protesting wage cuts outside Britain's House of Commons. 7. Corset Workers' Strike, 1937 Via coolrevolution.net As part of their strike, these members of the International Ladies Garment Workers Union marched in their corsets. 8. "Rosie the Riveter" Poster, 1943 Via floridatoday.com!-705203.jpg Rosie the Riveter has become a symbol of women's rights in the workplace — but that's not what this famous poster was originally supposed to convey (and in fact, the name "Rosie the Riveter" wasn't associated with the image until later). Sociologists Gwen Sharp and Lisa Wade write [pdf], "Ironically, the iconic image that we now imagine as an early example of girl-power marketing served not to empower women to leave the domestic sphere and join the paid workforce, but to contain labor unrest and discourage the growth of the labor movement." It was actually meant to encourage Westinghouse employees to work hard and be loyal to the company. 9. Bakery, Confectionary and Tobacco Union Protest, 1984 Via lennygreen.com Members of the union came together in Atlanta on International Women's Day to protest Ronald Reagan's policies. 10. Labour Party Pakistan Demonstration, 2008 Via chicago.platypus1917.org Women participate in a protest in the city of Lahore. 11. Coalition of Labor Union Women March, 2011 Via cluw.org Members of the Coalition of Labor Union Women march in favor of equal pay. 12. Kenya Health Workers' Strike, 2012 SIMON MAINA / Getty Images Nurses in Nairobi, Kenya, march for better pay.