On this U.S. day of rest known as Labor Day, IntLawGrrls offers a pictorial journey through the working life of American women 
and, alas, girls. Many of the early photos come courtesy of "A History of Women in Industry," an excellent exhibition at the website of the Washington, D.C.-based National Women's History Museum. 
At your leisure, have a look.
(image credits, top to bottom: early American spinner; 19th C. Navajo weavers; mid-19th C. domestic servants in Florida; early 20th C. cotton mill workers in Indianapolis, Indiana; early 20th C. farm worker; early 20th C., "Delia Kane, age 14, waitress at the Exchange Luncheon in Boston"; circa 1913, garment workers on strike in New York; 1937 photo of woman and child, forced by Depression and Dust Bowl joblessness to migrate from Oklahoma to California; circa 1940s photo of California Department of Motor Vehicles secretary Mitsuye Endo, a loyal American of Japanese ancestry who in a 1944 Supreme Court judgment won her challenge to internment; circa 1980s photo of Sally Ride, pioneering astronaut; photo of Maria Isabel Vasquez Jimenez, who, aged 17 and pregnant with child, died in 2008 of heat exhaustion while working in a field in California's Central Valley; March 2009 AP photo of Dr. Susan E. Rice, U.S. Ambassador to the United Nations (left), and U.S. Secretary of State Hillary Clinton (right), at work)
