The 7th Liberty 500-Mile Sweepstakes was held at the Indianapolis Motor Speedway on Saturday, May 31, 1919.

A riding mechanic was a mechanic that rode along with a race car during races, and who was tasked with maintaining, monitoring, and repairing the car during the race. The various duties included manually pumping oil and fuel, checking tire wear, observing gauges, and even massaging the driver's hands. They also communicated with the pits and spotted from inside the car. If the car ran out of fuel, or otherwise broke down, the riding mechanic was usually responsible for running back to the pits to fetch fuel or the necessary spare parts.