Before immigrants can become U.S. citizens, they have to pass an official test.
Recently, Newsweek magazine gave that same test to 1,000 Americans - and only 62 percent of them passed.
Twenty-nine percent of them didn't know the vice-president's name (Joe Biden) and 73 percent had no idea what the U.S. was fighting against during the Cold War (communism).
Newsweek Senior Writer Andrew Romano discussed the results on "The Early Show."
Co-anchor Erica Hill noted 23 percent of respondents didn't know what Martin Luther King Jr. did (fought for civil rights). Thirty-three percent, she said, didn't know when the Declaration of Independence was adopted (July 4, 1776). And only 37 percent knew there are nine justices on the Supreme Court.
Why don't people know these facts about their country?
Romano said, "There are a couple reasons when you talk to experts. One of the big ones is income inequality. We're one of the most unequal societies in the developed world. And when people don't have a lot of money, there is a difficulty getting a good education, there's a lack of opportunity and a lack of knowledge. That's one of the reasons why we don't do as well as northern European countries."
Hill asked, "So it's really a question of access?"
"It is," Romano said. "It's a big problem. We also have a very complicated system of government, much more complicated than some of these European countries. You have elections constantly for every imaginable office, you've got overlapping federal and state bureaucracies, and people kind of give up. They can't get their head around the whole thing."
Hill pointed out, "This isn't really a problem of -- or an issue, rather, a stupidity, it's more an issue of ignorance."
"That's exactly correct," Romano said. "There's a thing called deliberative polling that a professor at Stanford does. He gets people together in the room, polls them blind on a big issue, they have their opinions, they have their differences, but then they're confronted with the facts and they're forced to come up with a policy response to it. And almost every time, they come up with a rational reasonable policy response. So again, it's not stupidity, it's just a lack of knowledge on some of these issues."