Spain brought many goods from the Americas back to Europe, including tomatoes, potatoes, and tobacco. However, they also introduced the concept of slavery, with Queen Isabella struggling with the decision to allow enslaved people to be sold. The Spanish conquistadors had relations with native women, establishing a mixed-race population known as Mestizos and a complex caste system. They also spread Christianity while adopting local religious icons like La Virgen de Guadalupe to help convert the native population.