Likely football, although in the timeline I am writing on again and off again, baseball remains the most popular into modern times, but football is still big with most Americans preferring college football, over professional. Basketball is third, and hockey just hasnt caught on in most of the United States, anything hockey team below the Potomac River is unheard of. NASCAR itself doesnt become nearly as huge, sticking mostly to the southeast, but has tracks in California, Michigan, Arizona and after 1999 Cuba.