Make horse-racing more popular in the US and preferably throughout the West. Pre-1900 POD is fine too.
It doesn't have to be as popular as the NBA, the NFL, or college football, but it should be more popular than the NHL currently is, or golf.
Alternatively, make polo or some other sport that involves both men and animals more popular.
It doesn't have to be as popular as the NBA, the NFL, or college football, but it should be more popular than the NHL currently is, or golf.
Alternatively, make polo or some other sport that involves both men and animals more popular.