[3] Two drivers, Jerry Unser and Bob Cortner, were killed in separate crashes during the month.

[4] On the morning of pole day, Tony Bettenhausen suffered a bad crash during a practice run.

Bettenhausen escaped the crash with only minor injuries, and would qualify on the second weekend of time trials.

After three years of retirement, Duane Carter returned to the cockpit, and qualified for his ninth Indianapolis 500 start.

At the time the new world championship was announced and first organized by the CSI, the United States did not yet have a Grand Prix.

[15] The drivers also earned separate points (on a different scale) towards the respective AAA or USAC national championships.