Aussie Rules

This question presumably refers to the Australian Football League – but I only say that because the answer fits (the AFL was founded in 1896, as the Victorian Football League, and the first games were played in 1897).

But the sport was first played in 1858 (commemorated in a statue shown here on Wikipedia), and the first rules were drawn up in 1859; and the Victorian Football Association (VFA) was established in 1877. The VFL was founded as a breakaway by the bigger clubs, who wanted a greater share of the gate money. (Sound familiar?)

So it's actually more correct to say that the sport was founded in the 1850s, or the 1870s.

I would suggest however that you can't really say when a sport was founded. Better to ask when it was first played, or when the first rules were drawn up, or when any one competition was first held.