[May 19th, 1921] U.S. President Warren G. Harding signed the Emergency Quota Act, also known as the Dillingham Immigration Bill into law, limiting annual immigration from individual nations to no more than the number of people who had immigrated to America from those nations in 1910.
from /r/100yearsago
1921年5月19日]美国总统沃伦-哈丁（Warren G. Harding）签署了《紧急配额法》，又称《迪林厄姆移民法案》，将每年来自个别国家的移民人数限制在不超过1910年从这些国家移民到美国的人数。