I found a picture of the bison that Sir Alexander and his comrades bagged in South Carolina. Well, more or less. It's a real beaut, eh? From John Brickell’s The Natural History of North Carolina (1743):
THE Buffelo, or wild Beef, is one of the largest wild Beasts that is yet known in these parts of America; it hath a Bunch upon it’s Back, and thick short Horns, bending forward.
This Monster of the Woods seldom appears amongst the European Inhabitants, it’s chiefest haunts being in the Savannas near the Mountains, or Heads of the great Rivers.
Their Flesh is very course, and nothing to be compared with our Beef, but their Calves are said to be excellent good Meat, as in all probability they are: And it is conjectur’d that these Buffelo’s being mix’d, and breeding with our tame Cattle, would much improve the Species for largeness and Milk; for these Monsters (as I have been inform’d) weigh from 1600 to 2400 pounds Weight.
They are a very fierce Creature, and much larger than an Ox.