Roughly 1 billion people lived on our planet in 1800. And that was a pretty major deal, considering it took all of human history -- at least 50,000 years -- to reach that.
But today, just a little more than 200 years after, our population is at 7.2 billion and growing.
So what happened? How'd our population get so big? And how much room is left before we reach maximum capacity?
These two creative videos from NPR and the Population Reference Bureau illustrate how things got so crowded so quickly.