These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Both the original game and its remake have been criticized for allowing the player to exploit Native Americans and glossing over slavery.
Earn a Native Convert by founding a Mission and waiting a few turns. They have a higher yield on resource-gathering and a lower yield on manufacturing work. Put your newly-earned Native Convert to work in a silver mine. Failing that, a cotton or sugar plantation.