Europe’s revolutions of 1848 did not fulfill their goals for most participants and, as a result, many participants and supporters felt that the future in their European homelands was particularly bleak.

Enacted soon after the United States entered World War I in 1917, the Espionage Act prohibited individuals from expressing or publishing opinions that would interfere with the U.S. military’s efforts to defeat Germany and its allies.

Under this law, refugees became for the first time a major factor in U.S. immigration, and the administration of this law would influence subsequent policies on refugees, notably those from communist countries, including Hungary, Cuba, and Vietnam.

Immigrants played leading roles in the Civil War and the reconstruction of the South. Apart from slavery, few issues were as important in Civil War America as immigrants and immigration policy.