That's impressive video Human Population Through Time, which you will see below, describes the growth of the earth's population in the last thousand years. You will notice that it took a long time to populate explosion.
To become more specific we took 200 thousands of years to get the first billion people, but only 200 years to hit the landmark of seven billion. 
Watch the video with the map that tracks the growth of the world's population. The video shows how we spread around the world and highlights empires and historical events over the years.
The very interesting Human Population Through Time video that you will watch was uploaded to YouTube by American Museum of Natural History or American Museum of Natural History.
Watch it
