Why was the Indy 500 made?

Answer 1

The Indianapolis Motor Speedway complex was built in 1909 as a gravel-and-tar track and hosted a smattering of small events before the promoters decided to focus on just one major event. The creation of the first 500 mile automobile race allowed the track to rapidly acquire a privileged status for races.

Answer 2

It's a 500 mile car race held in Indianapolis, Indiana.