Recently arrived Irish immigrants in the the mid-1800s.

Ever since the first Europeans landed here over four centuries ago, America has had a conflicted relationship with its newcomers. It’s a serial drama that continues today in the halls of Congress, as legislators wrestle over a new round of immigration reform. We are, of course, a nation of immigrants, a destination for huge numbers of people from around the world. And the vast majority of us – everyone, in fact, except for American Indians – can trace our roots to foreign lands. Despite that common thread, though, America has not always treated its newest residents with empathy.

There have been four major waves of immigration to America, the last of which – mainly from Mexico, other Latin American countries, and Asia – continues today. Several themes play out consistently in all four chapters:

• Each successive wave of immigrants has been, to an extent, a reflection of social and economic conditions elsewhere in the world, and within the U.S. itself.
• Nearly every cycle of newcomers has faced animosity and backlash from already assimilated communities.
• The history of America’s immigration policy is a swinging door that often opens during periods of economic prosperity and slams shut when times get tough.

Scroll through the timeline below to follow the tangled history of America’s ever-changing immigration policies. (Easiest to view in full-screen mode) The interactive chart beneath it shows rates of legal immigration from 1820 to the present (use the scroll bar to zoom into specific chunks of time).

Number of Foreign-Born Legal Permanent Residents, 1820 to 2012

Source: Department of Homeland Security, Office of Immigration Statistics

View data table