How did john d. rockefeller horizontally integrate his monopoly in 1800?

Rockefeller used the size of his company Standard Oil to negotiate preferential rates with railroad companies to transfer his oil in the refinement process. By gaining the upper hand in transportation costs, he was able to horizontally integrate his competitors into his firm working to establish a monopoly in the American oil industry. 

Communicating with the dead was common, it wasn’t seen as bizarre or weird,” explains murch. “it’s hard to imagine that now, we look at that and think, ‘why are you opening the gates of hell? ’