What Is The Reason Behind The Large Percentage Of Roman Catholics In South America's Population?

The main reason for the enormous chunk of Roman Catholics in the statistical particulars of the population of South America is the fact that the first people who actually discovered, explored and later on inhabited this very region of the world were from the two strong Roman Catholic countries Spain and Portugal.

The first South American country, which was discovered and colonized by the Spaniards was Venezuela.  Christopher Columbus, who holds the credit to discovering America in 1492, also bears the honour of discovering Venezuela in 1498.  Later on settlers continued to come and settle in the region in the early years of the 16th century.  

However these historical conquests on behalf of Spain and Portugal were of a forceful and authoritative nature, where oppression and abuse were the order of the day.  This is the reason, which ultimately led to the revolt from the colonies in the early 19th century and then later on forming their own republics.