This conception is more mythos than reality. You should look at some of the early laws passed in many of these countries if you think we had a tradition of "strong" natural rights that are only being abrogated in our modern era.
It used to be illegal to publish content critical of the government [0], not to mention the fact that the franchise was restricted to those holding property, and definitely not considering ongoing active slavery.
I don't understand your connection to demonization of the poor.