These crimes took place despite the condemnation of the Catholic Church.
To take just one example: the matter of Indian slavery. Race-based slavery began in large-scale during the 15th century and was formally condemned by the Popes as early as 1435, fifty-seven years before Columbus discovered America. In reference to Spaniards who enslaved the natives of the Canary Islands (off the coast of Africa), Pope Eugene IV in 1435 wrote in a document called Sicut Dudum:
"...They have deprived the natives of their property or turned it to their own use, and have subjected inhabitants of said islands to perpetual slavery, sold them to other persons and committed other various illicit and evil deeds against them... We order and command all and each of the faithful ... within the space of fifteen days of the publication of these letters in the place where they live, that they restore to their earlier liberty all and each person of either sex who were once residents of said Canary Islands... these people are to be totally and perpetually free ..."
Those faithful, who did not obey, were excommunicated ipso facto. This is the same punishment Canon Law specifies today for Catholics who participate in abortion.
Yet there are 16 so-called Catholics in the US Senate who have consistently voted in favor of abortion-related measures, making them accomplices. To my knowledge none of them have been disciplined by their bishops. What should we conclude? That the Church has never taught against abortion ---- or that time and time again, the enforcement has been pathetically lax?
Strong doctrine, limp discipline. Another way of saying, as Jesus said of His own picked men, the Apostles, "The spirit is willing, but the flesh is weak."
I am still inspired by the Spanish conquistadors themselves. Yes, some of them were terrible men, but others were great men who helped destroy an evil empire or two that practiced human sacrifice and worshipped false gods.
Don't get me started on the racial/cultural apartheid that was brought to the hemisphere by the British Empire...