ITHACA, N.Y. — SEVENTY-FIVE years ago today, President Franklin D. Roosevelt signed the Fair Labor Standards Act to give a policy backbone to his belief that goods that were not produced under “rudimentary standards of decency” should not be “allowed to pollute the channels of interstate trade."

The act is the bedrock of modern employment law. It outlawed child labor, guaranteed a minimum wage, established the official length of the workweek at 40 hours, and required overtime pay for anything more. Capping the working week encouraged employers to hire more people rather than work the ones they had to exhaustion. All this came not from the magic of market equilibrium but from federal policy.

For decades afterward, Congress brought more people under the law’s purview and engaged in perennial struggles to maintain or increase the minimum wage. Fifty years ago this month, John F. Kennedy signed its most important amendment, the Equal Pay Act, which guaranteed women and others equal pay for equal work.

Despite this noble history, today the act faces an uncertain future, thanks to a series of disconcerting shifts in the way we think about work in America.