One of the best of many great lines in the 1992 US comedy My Cousin Vinny comes when New Yorkers Vinny Gambini and his girlfriend Mona Lisa Vito first arrive in the small rural Alabama town where the story takes place.

Looking around at a setting that makes rural Mayberry R.F.D. look like a metropolis, Mona Lisa says: "I bet they don't got Chinese here."

In many parts of the US, there are more Chinese restaurants than all of the Burger King, KFC, McDonald's and Wendy's fast-food outlets combined. More than 40,000, estimates Massachusetts Institute of Technology scholar Heather Lee, whose book in progress - Entrepreneurs in the Age of Chinese Exclusion - explores how an enclave ethnic business was transformed into one of the largest mass consumer industries in the US.

Between 1910 and 1920, the number of Chinese restaurants in New York nearly quadrupled, and doubled again over the following decade.

By 1920, Chinese restaurants in New York notched up $78 million in sales and rose to $154 million by 1930.

There have been plenty of theories on why it happened. Chinese food became popular because it was inexpensive, Chinese restaurants had later hours and often flamboyant decor.

Which helped. But Lee found something more.

The boom, it turns out, was actually an unintended byproduct of draconian US immigration laws. The notorious Chinese Exclusion Act of 1882 was still barring Chinese laborers, but it had loopholes.

Owners of certain businesses could obtain "merchant status" that allowed them to enter the US and sponsor relatives, and in 1915 a court ruling added restaurants to the list. A boom was born.

The Chinese pooled their resources into partnerships and opened luxury "chop suey palaces" with startup capital ranging from $90,000 to $150,000 (in 2015 currency). Investors would take turns being "the owner".

The average chop suey palace employed five waiters and four cooks and most were supplied by extended families, working long hours for little money. Lee estimates that the average employee at a chop suey palace made a third less than the national average for food service employees.

The entrepreneurs were able to overcome harsh immigration barriers to pay investors annual dividends as high as 10 percent and handsome salaries. Much of the money they sent back home.

Lee found that families in China with relatives in the US enjoyed monthly incomes three times larger than families with no members in the US. In some cases, the income was used for community projects like schools, hospitals and even railroads.

"In many ways," Lee concludes, "the US Chinese restaurant industry built fortunes in two vast nations."

Contact the writer at chrisdavis@chinadailyusa.com