Isthmian Steamship was the brainchild of US Steel President James A. Farrell, who had connections with the maritime industry through his father's trade as a ship's master.

The company's first ship was Bantu, a British steamship launched in 1902 and bought by US Steel from the Bucknall Line in 1910[1] for a reputed £24,000.

[4] She was joined in 1914 by another newly-built ship, San Francisco, from the North of Ireland Shipbuilding Company in Derry.

In 1956 however, the by then highly lucrative company, then under retired Vice admiral Glenn B. Davis, was sold to States Marine Lines.

US Steel justified the sale on the grounds that Isthmian's overall usefulness had diminished, as it now carried only a fraction of the corporation's exports.