See the long list of animals that already had disappeared from the continent before Columbus set foot on it.

"Before humans entered the picture (during the last ice age, roughly 13,500 years ago) North America had an impressive assortment of large mammals and birds. [...] The fate of all these species has been the topic of much scientific debate, but the majority of the evidence supports the hypothesis of “Pleistocene Overkill” (Martin and Wright 1967, Flannery 2001). This hypothesis suggests that [..] they preyed upon the large herbivores, such as mammoths, ground sloths, and horses, and wiped them out. "

https://www.marinebio.org/creatures/essays-on-wildlife-conservation/3/