"The essence of antitrust law is to try to keep the system working by recognizing that, at certain points, some companies may get too big for their own good, they're self-imploding, or the technology may become so dominant that it's just crushing all other elements where there can be innovation."

- Judge Leonie Brinkema, 2023, United States v. Google LLC

In the late 1930s, it appeared as if Antitrust Division chief Thurman Arnold had tamed the business world, having filed so many antitrust suits with such effectiveness that there was no longer any resistance. In his first year, Arnold filed 1,375 complaints in 213 cases in 40 different industries, from cars to housing to milk to movies. When enforcers merely launched an investigation, prices dropped by 18-33 percent because businessmen wanted to get ahead of any possible violations.

There was still a lot of brutal fighting ahead, but in a sense, the old order in the business world had been morally defeated, exhausted by years of legal combat.

The new order was immensely profitable, far more than that of the 1930s. Some of the highest corporate profit margins in American history were in the 1950s, but corporate leaders knew they had a broader responsibility to society. And it wasn't nonsense corporate social responsibility rhetoric we hear about today, but a realization that rapacious behavior would bring swift legal consequences.

It worked. "The Money Trust has disappeared, and Wall Street is a symbol only to students and those with long memories," wrote economist Carl Kaysen in 1954. John Maynard Keynes had penned a private letter to Franklin Delano Roosevelt about business leaders. He wrote, "You could do anything you liked with them if you would treat them (even the big ones), not as wolves or tigers, but as domestic animals by nature, even though they have been badly brought up and not trained as you would wish." FDR tamed big business.