What business model did Andrew carnegie use as a model?

Andrew Carnegie employed a vertical integration business model, which involved controlling all aspects of production from raw materials to finished products. He strategically acquired steel mills, iron ore mines, and transportation networks, allowing him to reduce costs and increase efficiency. This approach enabled Carnegie Steel to dominate the steel industry in the late 19th century, leading to significant profits and growth. Additionally, his focus on innovation and technology played a crucial role in his business success.