Here is an absolutely amazing video that shows the growth of Walmart since 1962 .
It was done by software developer Toby Segaran. He say about this project. "To create the animation, I generated 30 images for each year starting with 1962. I spread all the Wal-marts that opened that year over the 30 frames. To show the appearance of a Wal-mart, all I had to do was plot a large white dot over the small yellow dot for the appropriate ZIP code."