By Life in the USA
Any study of the American people must take into account how complicated that subject is. The United States is a large country encompassing more than 300 million people. Indigenous people (today called Native Americans) make up at most 2% of the American population today. The other 98% are either immigrants or descendants of immigrants.
Many people came to the United States to seek economic opportunity or religious freedom. Others came as slaves. Some groups, including many from the British Isles, became well established by the time of American independence from Great Britain in 1776. Others, like the Irish and many Germans, came in waves during the 19th century.
Asians came in their own waves, especially over the past half century. So-called Hispanic people (actually a very varied group) could be descendants of 17th century settlers from Spain, or they could have arrived in the United States last week (or any time span in between).