I am not a proponent of government; I am a proponent in the efficient functioning of markets and against concentrated power in all forms. You seem to be fine with concentrated private power, but no governmental power.

You are right that there are governmental caused monopolies. Sometimes these are justified such as natural monopolies (even though these are not really created by the government but rather public ownership is better than are private). Other times this occurs based on regulatory capture (which are bad and should be disbanded), or based on legitimate public concerns. Doctors and lawyers have a monopoly on their professions enforced through the governmental systems, but based on the fact of incomplete knowledge on the part of consumers these seem reasonable at least theoretically. Note, sometimes these groups can take advantage of such things and should be quashed. Other examples of monopolies that seem ok in theory are patents, trademarks, etc.

But this is not really what I am talking about. I am talking about "big railroads" and "big steel" and "big coal" and "big shoe". In the gilded age these monopolies arose naturally and used their private power to crush competition. This wouldn't be a problem if there were no barriers to entry. You talk about regulatory barriers to entry, but you have to be blind if you don't realize that there are natural barriers as well as legal ones. The reason you don't go out and start a new Wal-Mart is not because of some government license you need, but because you know that you would be crushed.

As for your point on Jim Crow, it is overly simplistic, you are being disingenous about private citizen racism in the 1960s, and you get the causation backward. In most areas of everyday life, laws did not force segregation (school and common carriers are the exceptions). It was private citizens who chose to do so.