What business practice contributed most to Andrew Carnegies ability to form a monopoly?

Andrew Carnegie's ability to form a monopoly was primarily attributed to his implementation of vertical integration. By controlling every aspect of the steel production process—from raw materials to transportation and distribution—Carnegie was able to reduce costs and improve efficiency. This strategy allowed him to dominate the steel market, undercut competitors, and ultimately establish a powerful monopoly in the industry. Additionally, his focus on innovation and technology further solidified his position as a leader in steel production.