Each year, millions of people from countries around the world immigrate to the United States, ranging from tourists visiting for a couple weeks to workers coming for a job to refugees escaping persecution. The number of people coming to the US, where they come from, and why they come has changed significantly over time.
In 2015, 8.5 million people visited the US for tourism or short-term business on B1 and B2 visas. The US also participates in the Visa Waiver Program, which allows visitors from select countries, mainly European countries and allies such as Japan and Australia, to visit the US for up to 3 months without a visa.
3.5 million people, less than half the number of temporary visitors, came to the US in 2015 intending to stay for a longer time. Many came for work, school, and to be with family. The rest came to seek safety (refugees and asylum-seekers fall in this category) or were admitted through diversity lotteries.
State Department, Nonimmigrant Visa Statistics; Department of Homeland Security, [Yearbook of Immigration Statistics (https://www.dhs.gov/immigration-statistics/yearbook)
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