What business practice contributed most to andrew carnegie’s ability to form a monopoly?

Carnegie invested in steel during the 1870s and gradually created a vertical monopoly by buying out companies at every level of the production of steel, from raw materials to distribution of the finished product. He then combined these into one company, Carnegie Steel, and, at the turn of the 20th century, merged with US Steel. This made them the largest company to exist and gave him a monopoly on the steel industry.

$2.00 for three shots.

answer; customers within the organization