“They started bringing in foreigners in the 60s to appeal to the world as opposed to only Americans.”
Not entirely true. Foreign drivers have run Indy almost since the beginning; the 1913 race was the first one won by a foreigner. Also, from 1950 to 1960, the Indy 500 was a points-paying event in the World Driving Championship (and the only one not run to Formula One rules).
” Foreign drivers have run Indy almost since the beginning;”
Yes, I am aware of that. However, if you look at history, in the 60s there was an influx of foreigners.