When Amsterdam is in the past with the Lenape, tepee/tipis are shown as their dwellings. Tepees are Plains Indians structures; the Lenape and other east coast groups were mostly settled and lived in longhouses and other such structures.
John is said to have an extremely rare blood type, a form of RzRz, that became extinct when certain Native American tribes disappeared. Yet blood typing has only been around since the early twentieth century, long after the tribe that saved John had ceased to exist.