Though Africa has a large number of people escaping war, living in poverty, and suffering from unstable governments, relatively few Africans have been able to immigrate to the United States because of the cost and distance. Some African immigrants have used the refugee visas or so-called lottery visas via the Diversity Visa Program (1990). Some Africans also come to the US for advanced education. Many African immigrants are sponsored by other relatives for family reunification.
Many migrants from Europe came to the United States directly or indirectly because of the economic hardships or violent conflicts of communism. Some came looking for more financial opportunities, and others escaping from wars that broke out as the Soviet domination of Eastern Europe fell apart in the 1990s.
People coming to the United States from the Middle East are primarily escaping the direct impact of war. For decades, violent armed conflict has characterized many parts of the Middle East, especially in Palestine, Syria, Iran, Iraq, and Afghanistan. The United States has had both direct and indirect roles in these wars, roles that have ranged from arming one or both sides to actual invasion and occupation.