The debate between welcoming migrants and protecting the U.S. from perceived external threats is one that has pervaded the American history. It’s a debate that, or one time or another, has determined the fortunes of practically every ethnic group in America. America is a nation of immigrants and refugees, but also a nation that has, on countless occasions, turned immigrants and refugees away.

Perhaps the first unwelcomed “refugee crisis” was massive influx of Irish migrants to the U.S. in the mid-19th century, which provoked one of the most significant anti-immigrant movements in American history.

Others fled natural disasters, Italian immigrants who came to America in 1909, after an earthquake.

The Mexican revolution also began in 1910, leading to the flow of one million Mexicans into the U.S. over the next two decades.

In the late 1930s, Americans were also reluctant to welcome Jewish refugees of the brewing Second World War.

More recent waves of refugees coming to the U.S. have also drawn opposition. Others, like the Kurdish children in the 1990s, were sent to Guam, where they endured lengthy waits while their applications were reviewed

During many of these crises, public opinion over whether to accept refugees was mixed. In the Hungarian, Indochinese and Cuban refugees crises of past decades, the majority of Americans believed we should not accept refugees; only in the 1999 Kosovo conflict did most Americans support welcoming refugees to the U.S.