Modern migration has barriers that traditional migration did not have. Nowadays, people must face political processes when they want to cross national borders. Sometimes the political forces limit modern migration to select groups of people. People frequently migrate for better jobs and economic opportunities, which is the reason so many people are trying to migrate from Mexico to the United States right now. In the 1980s in the United States, migration started shifting from the north to the south as new industries in the south began to open up and provide job opportunities for people.
Migrants retreat to Mexico during a failed attempt to illegally enter the United States. (David McNew/Getty Images)
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