Post World War II, the Lower East Side's changing immigrant communities reflected a shift in policies that were taking shape on the national level. The Johnson Reed Act of 1924, which restricted European migration, contributed to the Lower East Side's diminishing Jewish community, but the United States opened its doors again in 1945 to welcome 140,000 Jewish refugees. Chinese immigrants began to move in after the Chinese Exclusion Act was repealed in 1943. Also during this period, the war effort and postwar economic policies caused a boom in manufacturing jobs, attracting Puerto Rican migrants to the city. The Lower East Side soon became a bustling neighborhood on the periphery of two emerging immigrant enclaves: Chinatown and Loisaida.