The Native Americans of North America were fairly content in their lives before the British and Spanish came along and invaded their native land. The Native American civilizations in Mexico attributed their size and sophistication to agriculture, more specifically corn growing. When the British and Spanish arrived, however, many things about the Indians were changed both culturally and economically. Their lives would never be the same.
European explorers marveled at the sight of iguanas, rattlesnakes, tobacco, maize, beans, tomatoes, and lowly potatoes. These new crops revolutionized the international economy not to mention the European diet. In 1493, Columbus unloaded at Hispaniola twelve hundred men, cattle, swine, and horses. The horses soon reached the North American mainland through Mexico and in less than two centuries spread as far as Canada. Indian tribes like the Apaches, Sioux, and Blackfoot quickly adopted the horse. The horse transformed their cultures into highly mobile, wide-ranging hunters. A "sugar revolution" took place after the sugar cane seedlings Columbus had brought prospered so greatly in the Caribbean climate. .
More importantly, the Europeans brought with them many diseases including smallpox, yellow fever, and malaria. These diseases devastated the Native Americans. Within fifty years of the Spanish arrival, the population of the Taino natives in Hispaniola dwindled from one million to two hundred. In total, nearly 90 percent of the Native Americans perished because of their Old World "friends". The amount of death was so bad that entire cultures and ancient ways of life were gone forever. .
Spain became the dominant exploring and colonizing power in the 1500s. The Spanish conquistadors eventually made their way into North America. Hernando de Soto undertook a gold seeking expedition during 1539-1542. He discovered and crossed the Mississippi River.