Are you now trying to runaway from the examples you repeatedly cited?
This is exactly why I insisted on you citing a specific example. Your tactics are tired and weak.
Let's look at some of your other examples of monopolies that could only be stopped by government regulation.
US Steel held a 67% share of the market upon its formation in 1901. It never again saw it's market share reach that high and declined steadily from that point forward. The government attempted an antitrust action in 1911 (at which time US Steel's market share had already declined to 50%) to break it up but failed. It now controls 8% of the US market and that had nothing to do with government regulation. US Steel failed as a monopoly because it could not keep smaller competitors, like Bethlehem Steel, out of the market and it's largess made it less innovative.
The International Mercantile Marine Co., was formed in 1900 and was in receivership by 1915. Morgan lost a shit ton of money. The government did not break it up, it simply failed. In fact, the government tried to subsidize the floundering company with the Frye-Payne bill.