This chart shows where U.S. immigrants came from over the past 200 years, measured as a percentage of the U.S. population at the time. Max Galka crunched the numbers and made an interactive map showing the places U.S. immigrants have come from between 1820 and 2013. At Metrocosm, you can adjust the slider to check out different years or just let it play, like this video.
Each dot represents 10,000 people. The 79 million people who immigrated to the U.S. during that period only include those who became permanent legal residents. -via Boing Boing
If it was more common knowledge, people would probably demand the process be simplified.
I don't know how many people could manage without money and legalese-sense. And judging from how family and friends have reacted throughout the process, a lot of people have no idea what immigration to the US involves these days ("Oh, she's your wife, you can just simply...")