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Who is rich in America, and how did they get there?

That’s the central question of an eye-opening new book, The Everywhere Millionaire, by two economists who have spent more than a decade researching the wealthiest Americans. Their answer challenges the popular narrative that America is in a new Gilded Age dominated by a small number of spectacularly rich billionaires.

Look beyond Silicon Valley. Look beyond Wall Street. There’s a much larger class of wealthy Americans hiding in plain sight. They’re all around the country. And, often, they got rich in mundane ways. They own car dealerships. They sell hot dogs and frozen mini-quiches. They run waxing salons. They supply fabricated metal and urinal cakes. They are dentists.

Collectively, these “Main Street millionaires” control much more wealth than the billionaire lightning rods who launch rockets into space, appear on manosphere podcasts, and have Hollywood movies made about them. Many of these millionaires have also grown rich enough to afford superyachts, 10,000-square-foot homes, and pet tigers. And the book suggests that, as a group, their political power can rival that of the billionaire “oligarchs.”

At the center of their story is a quiet revolution in the American economy: the rise of a particular kind of private business. A few decades ago, these businesses collectively made far less money than Corporate America. But by 2011, they were generating more income than all traditional U.S. corporations combined — and accounting for most of the rise in the share of income flowing to the top “one percent.”

The book estimates that there are about three million of these private business owners in the United States. And they’re each, on average, worth around $25 million.

The Everywhere Millionaire paints a complicated picture of these millions of Main Street millionaires. Some embody the American Dream: self-made entrepreneurs who rose from rags to riches by offering consumers better products and services.

But there’s also a darker side to the story. The book shows how many Main Street millionaires have used their clout to shape public policy in their favor. They’ve triumphed in major battles to lower their tax bills. And, in many industries, they’ve fought for — and often won — rules and regulations that can protect their profits and raise costs for consumers.