They were from Spain. They were exploring North America. They were trying to find away through North America. They tried that because they wanted a faster route to China. They never found a route through North America. In 1519 they sailed out.
Cortes had horses and lots of men that he had come with him. He had small boats. The boats were for getting though the small streams and rivers. Some of the other expeditions were for trade and and search for Christian captives.