john d. rockefeller came to control the oil industry. and his control, his monopoly is horizontal. o, we've got five steps. john d. rockefeller did not owned all the oil wells in america, okay? he didn't own all of the pipelines or the railroads that are going to transport that crude oil. but what he did own was that third process. rockefeller owned over 90% of the oil refineries in america. so, if you were taking crude oil out of the ground, you hit a gusher down in west texas, you're going to have to go to a standard oil refinery for it to be processed into a usable, sellable product. he owns over 90% of that horizontal level, the refineries in america. which means, then you have to do business with him. he would say, here is what the price is going to be. you would say, now, that's too high. good luck finding another refinery. oh, wait a minute, i own over 90% of them. you're going to have to do business with me, which means i can set the price as high as i want. because i have no competition. rockefeller doesn't own the railroads that will take that finished product down to sail