Here's why:
* Language: Spanish is the dominant language in most of Latin America, spoken by a majority of the population in 20 countries. This is a direct result of Spain's colonization of the region, which began in the 15th century. Spanish replaced the indigenous languages in many areas, though some indigenous languages still survive.
* Religion: Catholicism is the predominant religion in Latin America, a legacy of Spain's influence. Spanish colonists brought Catholicism with them and actively sought to convert indigenous populations. This led to the widespread adoption of Catholicism throughout the region.
While other European powers, such as Portugal (Brazil) and France (Haiti) also had their influence, Spain's dominance in terms of both geographic reach and duration of colonization made it the most significant factor in shaping the language and religion of Latin America.