(US,historical) A loophole in early-1900s American immigration law that allowed Chinese people to enter the country if they managed a Chinese restaurant, resulting in a greater-than-average increase of those establishments over several decades.
2016 February 22, “Lo Mein Loophole: How U.S. Immigration Law Fueled A Chinese Restaurant Boom”, in National Public Radio[1], retrieved 2023-06-18:
"Lo Mein Loophole: How U.S. Immigration Law Fueled A Chinese Restaurant Boom [...] Some Chinese business owners in the U.S. could get special merchant visas that allowed them to travel to China, and bring back employees. Only a few types of businesses qualified for this status. In 1915, a federal court added restaurants to that list. Voila! A restaurant boom was born."
