How the buffalo (bison, to your foreigners) survived to become the US national mammal:
In the early 1800s, there were more than 30 million buffalo in North America, ranging in massive herds from Alaska to Mexico. By 1890, only about 500 animals were left. By the early 1900s, there were only about 30 genetically pure animals surviving in isolated areas, such as private ranches and the Yellowstone caldera.
Well, the bison ecological niche was replaced by herds of semi-domestic cattle but sheesh - I thought people were the national mammal.