When were the first horses seen?

since the very first day GOD created the heavens and earth. there were two of each animal in the garden of eden. (the first day of everything we know).

Answer2:

The above answer is the religious answer. For scientific minded people the answer would be 65 million years ago. Horses evolved from small fox sized multi-toed forest browsers. As the forests gave way to grasslands the toes slowly began to change and morph into one hoof per leg and the horse became taller to see over the long grasses and to flee from predators. The horse also developed an elongated skull with eyes placed more to the side for better vision while grazing on the long tough grasses.