Can-Am, formally known as the Canadian American Challenge Cup, was a form of no-holds-barred motorsport with approximately three rules: have a seat, be kind of safe, and make sure the wheels are enclosed. That’s it. As you can imagine, it made for some absolutely absurd cars and some equally absurd racing.
Teams like Porsche and McLaren developed special prototypes for Can-Am, while smaller carmakers like Chaparral made their name in the sport with innovations that seem almost ridiculous to think about. Sure, Lotus might have introduced wings to Formula 1, and Brabham might have brought in the fan car, but both of those ideas were pulled straight from Can-Am.
The series ran in two different iterations, one from 1966 to 1974 and a second from 1977 to 1987. Both iterations ultimately failed because that lack of ruleset meant big-budget teams could outspend the little guys and develop wildly sophisticated racing machines that stood no chance of ever being beat. Paired with things like the oil crisis of the mid-1970s, folks started withdrawing, and soon all that was left were privateers.
I could sit here and recount the whole history of the series to you — or I could just direct you to this incredible video from Driver61 that talks about the exact same thing but with tons of amazing visuals, like breakdowns of the cars and old race footage.
When you boil it down, though, what you end up with is a race series that absolutely should not have existed, and yet one that produced some of the coolest shit the racing world has ever seen. Engineers were experimenting with aerodynamic concepts in Can-Am long before anyone in Formula 1 got clued into that particular revolution, and it firmly established North America as a premiere racing location. Sure, we had stock car racing and open-wheel events, but Can-Am captured the imagination in a totally different way.