History of the 40-hour workweek

It took nearly a century for the eight-hour workday to become standard in the US. David S. Holloway/Getty In 1890, the US government began tracking workers' hours . The average workweek for full-time manufacturing employees was a whopping 100 hours .

Seventy-five years ago, on October 24, 1940, the eight-hour day and 40-hour workweek became standard practice in a range of industries. It was a long, drawn-out battle between workers and government officials.

We take a look back at the history of the 40-hour workweek, as well as how it's evolved in the last few years.

The history of the 40-hour workweek

August 20, 1866: A new organization named the National Labor Union asked Congress to pass a law mandating the eight-hour workday. Their efforts technically failed, but they inspired Americans across the country to support labor reform over the next few decades.

May 1, 1867: The Illinois Legislature passed a law mandating an eight-hour workday. Many employers refused to cooperate, and a massive strike erupted in Chicago. That day became known as "May Day."

May 19, 1869: President Ulysses S. Grant issued a proclamation that guaranteed a stable wage and an eight-hour workday — but only for government workers. Grant's decision encouraged private-sector workers to push for the same rights.

1870s and 1880s: While the National Labor Union had dissolved, other organizations including the Knights of Labor and the Federation of Organized Trades and Labor Unions continued to demand an eight-hour workday. Every year on May Day, strikes and demonstrations were organized to bring awareness to the issue.

May 1, 1886: Labor organizations called for a national strike in support of a shorter workday. More than 300,000 workers turned out across the country. In Chicago , demonstrators fought with police over the next few days. Many on both sides were wounded or killed in an event that's now known as the "Haymarket Affair."

1906: The eight-hour workday was instituted at two major firms in the printing industry.

September 3, 1916: Congress passed the Adamson Act , a federal law that established an eight-hour workday for interstate railroad workers. The Supreme Court constitutionalized the act in 1917.

September 25, 1926: Ford Motor Companies adopted a five-day, 40-hour workweek .

June 25, 1938: Congress passed the Fair Labor Standards Act , which limited the workweek to 44 hours.

June 26, 1940: Congress amended the Fair Labor Standards Act , limiting the workweek to 40 hours. The act went into effect on October 24, 1940 .

Technological advances allow us to work around the clock. Shutterstock

How the 40-hour workweek has evolved

Recent research suggests that the 40-hour workweek may be on its way out — at least among professionals and executives.

In a survey by tax and professional services firm EY, half of managers around the world reported logging more than 40 hours a week. In the US, a whopping 58% of managers said they worked over 40 hours a week. Presumably, some of that time is spent at home answering emails, instead of at the office.

Meanwhile, there's evidence that some Americans see working around the clock as a kind of status symbol . While many people claim to be working 60- or 80-hour workweeks, much of that time isn't very productive. In fields like finance and consulting, some workers may only be pretending to work 80-hour weeks, a recent study suggests.

Yet for lower-income Americans, who may not view overwork the same way, there are some signs of progress.

In June 2015, Congress proposed a rule change that would expand the number of Americans who qualify for overtime pay. Workers who earn up to $50,440 a year would be eligible for time-and-a-half overtime wages when they work more than 40 hours per week. Currently, the threshold below which workers can earn overtime wages is just $23,660.

No matter your profession, the truth is that working longer hours can be counterproductive because you start putting out lower-quality work as time goes on.

In general, research suggests that we can handle working 60-hour weeks for three weeks — after that, we become less productive.