North America's horses had been extirpated long before the rise to power of the Aztec civilization.
See the related Wikipedia link (Equus scotti) listed below for more information:
The Spaniards brang European men with diseases that the Aztecs were not naturally immuned to. The Spaniards also had armor and weapons that were made out of stronger material. The Spaniards had horses too.
horses
The Spaniards attacked the Aztecs during a festival
why did the spaniards treat the Aztecs harshly
The Spaniards who rode horses were the first to introduce this animal to the Aztecs and Incas, as these civilizations had never encountered horses before the arrival of Europeans in the 16th century. The use of horses provided the Spaniards with significant advantages in mobility and warfare, impacting their conquests in the Americas. The sight of horses was both surprising and intimidating to the Indigenous peoples, who had only ridden llamas and other native animals.
In the Aztec account, the tall "deer" that carried the Spaniards on their backs refer to horses. The Aztecs, unfamiliar with horses, likened them to large deer due to their size and the way they moved. The arrival of the Spaniards on horseback had a significant psychological impact on the Aztecs, contributing to the confusion and fear during the initial encounters.
The Spaniards were wanted to conquer the Aztecs and take all of their property, and the Aztecs didn't want that.
Small pox wass brought with the Spaniards which the Aztecs couldn't cure and, well, the Spaniards had cannons, horses and guns. (Instant ownage against clubs.)
They killed the Aztecs
the Spaniards defeated the Aztecs.
At first, the Aztecs thought that the Spaniards were gods because of their shiny armors and their weapons. When the Spaniards conquered them and onward, however, they feared them.
the Spaniards