Lasting effects of Spanish conquest in Latin America included the decimation of native populations and suppression of their languages, histories and cultures. Those who survived were strongly influenced by Spanish language, religion, art and architecture.
One of the greatest lasting effects of Spanish incursion into Latin America was the devastating loss of indigenous populations. Some of the main culprits were smallpox and other diseases against which native people had no defense. Additionally, the encomienda system of forced slavery of locals killed many more natives through hard labor and privation.
Existing native leaders were killed or stripped of power, leaving indigenous societies without the social structures on which they depended. Spanish priests outlawed local religion and culture and burned written histories, leaving a cultural vacuum. As a result, indigenous societies whose people numbered in the millions before Spanish conquest were marginalized or obliterated.
In the absence of indigenous alternatives, Spanish language and culture became dominant in Latin America. Spanish became the primary language in many Latin American countries. When it was first introduced, many native South Americans melded Roman Catholicism into their traditional religious practices. Over time the Roman Catholic religion became the predominant theological influence in Latin America. Spanish architecture formed the basis for many structures, and town planning was based on the layout of a plaza or town square in the midst of a municipality.