I'm guessing cattle became the new large herbivores.
Hard to say what is actually still eating them. Some claim horses will if given the chance and the rapid spread of Osage after horses were re-introduced may have something to do with that but one definite reason is that people nurtured the species by helping it establish itself as a fencerow tree.
It's kind of interesting that the Indians didn't seem to try planting it in areas well outside where they had to travel to get it since it will grow over a huge range if allowed.
The practice of planting stuff where it is needed was well known for trees with other uses.
The most remarkable example I have seen is a park comprised of pure Hackberry in Carleton Place, Ontario. Hackberry is probably nearly unheard of in Ontario except in the extreme southwest. Carleton Place is considerably off that area.
The theory is that the trees were established by Indians portaging at that point on the river as a source of anti-inflammatories.
