Focusing on the period from 1924 through 1965, Ngai describes how US immigration policies were shaped by world events. The United States’ entry into World War I was controversial, with many protesting against it. Although Americans from all backgrounds protested the war, opposition to the war became associated with southern and eastern European radicals in the American imagination. In the war’s aftermath, the number of displaced persons rose and those opposed to immigration argued for restrictive laws. The 1924 Immigration Act favored northern European over southern and eastern European immigration, completely excluding Asians and Africans. However, as a result of the earlier Spanish-American War, the US possessed the Philippines as a colony. Agribusinesses therefore recruited Filipino immigrants, who could come to the US with no restrictions. When white individuals objected to their presence, they successfully lobbied for Filipino independence and stopped the flow of immigration.

Given the scarcity of work and poverty during the Great Depression in the 1930s, Mexican workers, both citizens and immigrants, faced a hostile environment and were expelled from the US in large numbers. World War II changed the fortunes of Chinese Americans and immigrants due to China’s alliance with the US. The Chinese Exclusion Act was repealed in 1943, but relations turned with the Communist Revolution in China and the onset of the Cold War.