Subsequently, the plant was modernized and expanded by August Thyssen, becoming a vertically integrated company producing iron and steel and manufacturing ships, machines etc.

After the First World War came the occupation of the Ruhr and the loss of many foreign interests; however the company remained viable.

The other mills of the company in Duisburg became legally independent entities; in the 1950s and 1960s they were reintegrated into the Thyssen group.

In 1954/55, the group focused on acquisitions to restore the vertical integration by acquiring mining concerns.

[1] In 1997, the flat steel production divisions of both groups were merged to form Thyssen Krupp Stahl AG.

The discussions failed because Liberty wanted TK to pay money for the privilege of losing the Duisburg plant from its balance sheet.