This push to enhance workers’ freedom to strike is more consequential than it might look at first glance. Conflict was the engine of labor reform in the 1930s. And mass strikes and picketing, in particular, pushed the federal government to act.

In 1934, the historian Irving Bernstein writes in “The Turbulent Years: A History of the American Worker, 1933-1941,” “there were 1856 work stoppages involving 1,470,000 workers, by far the highest count in both categories in many years.” In that year, nearly five years into the Great Depression, “labor’s mood was despair compounded with hope.”

The despair was self-explanatory. The hope came from the growing conviction that workers had to act of their own accord — to, Bernstein wrote, “take matters into their own hands and demonstrate their collective power to recalcitrant employers through the strike.” And strike they did.

In Toledo, Ohio, for example, workers demanding union recognition organized a strike against Electric Auto-Lite, an automobile parts manufacturer, and its related firms. When Auto-Lite and its partners hired strikebreakers and kept their factories open, the union worked with the American Workers Party, a small, radical political party that organized jobless workers to keep them from breaking strikes.

Together, unionists and labor radicals led mass pickets against Auto-Lite. Thousands of workers, employed and unemployed, surrounded the plant. Fighting broke out when a strikebreaker attacked a striker. The police and company guards attacked, and a battle ensued. The National Guard arrived and the fighting continued. In their attempt to break the siege and evacuate the strikebreakers, troops killed two strikers and injured more than a dozen others. After a week of violence, Auto-Lite agreed to close the factory. The next month, after additional mass protests and the threat of a general strike, the company backed down, recognizing the union and agreeing to rehire the strikers.