Conversation so far:
what is warfare?
Three factors led to a growing importance of warfare in Plains Indian culture.
what was the first factor?
First, was the Spanish colonization of New Mexico which stimulated raids and counter-raids by Spaniards and Indians for goods and slaves.
what was the second factor?
Second, was the contact of the Indians with French fur traders which increased rivalry among Indian tribes to control trade and trade routes.
what was the third factor?
Third, was the acquisition of the horse and the greater mobility it afforded the Plains Indians.

Question: did the plains indians get horses?
Self-contained rewrite: did the plains indians get horses?