What major global event in the early 20th century led to a rise in anti-immigrant sentiment in the U.S.?

World War I significantly influenced anti-immigrant sentiment in the United States during the early 20th century. The war heightened nationalistic feelings and often led to the perception of immigrants, particularly from countries that were enemies or involved in the war, as potential threats or disloyal. Propaganda during this period emphasized loyalty and patriotism, casting suspicion on foreigners and immigrants who were seen as un-American.

As society grappled with the effects of the war, including economic shifts and social tensions, the fear of espionage and sabotage further fueled prejudice against immigrant communities. This environment contributed to the implementation of stricter immigration laws and the promotion of nativist policies in the years following the war, particularly exemplified by the Immigration Act of 1924, which aimed to drastically reduce immigration from certain countries.

Other events, such as the Great Depression, came later and had their own impacts, but the direct influence of World War I on national sentiments towards immigration was particularly pronounced. The Civil War, while it created divisions within the country, was a different historical context focused more on internal conflict rather than the foreign influences that shaped views on immigration in the early 20th century. The Vietnam War occurred much later and did not have the same immediate effects