In which century did Canadian football originate?

I like the larger field and "3 down format" of Canadian Football as opposed to the smaller fields and "4 down format" of standard American Football...

its 21st not 21th

So we’re calling it the 21th century?

SMD, Canadian football & American football (gridiron), are different games. Both games have their origins based in Rugby. However, each evolved separately. Though very similar, they each have distinct differences.