During the 1800s it was common place for factory workers to complete on average 100+ hours a week.
Seventy five years ago, October 24, 1940 the eight hour day and 40 hour work week became standard practice after a long battle between workers and government officials. The Fair Labor Standard Act established the 40 hour week.
The 40 hour a week law establishes that if you work over 40 hours that anytime over that you are paid at least 1 and 1/2 time your pay per hour. It however does not mean your boss can not mandate you to work over 40 hours a week