How many people live in USA I think 10 billion
As the worlds'7 billionth baby was just born the other day, I believe EmtLyndsey is correct.
More like 310 million according to the 2011 census and that's not completely true as some people don't complete their census.
Seems like a trillion but it's about 310 million
310,872,000 live in the North America.
The population of US is little more than 310 million, and the total world population is 7 billion and counting. US is the third most populous country of the world after China and India.