The first container ship voyage occurred in 1956.
On 26 April 1956, the converted tanker Ideal X sailed from Port Newark, New Jersey, to Houston, Texas. It carried 58 standardized 35-foot containers on a specially fitted deck, alongside a conventional cargo of petroleum. The voyage is widely regarded as the beginning of modern container shipping.
The idea came from American trucking entrepreneur Malcolm McLean, who recognized that cargo could be moved more efficiently in detachable boxes instead of being loaded piece by piece. This reduced loading time, theft, and handling damage while allowing ships, trains, and trucks to work as one integrated transport system.
Earlier experiments had carried cargo in boxes, but the Ideal X voyage demonstrated a commercially practical model. Containerization expanded rapidly afterward: Sea-Land began regular services, and the first transatlantic container service followed in 1966. The familiar 20-foot and 40-foot containers became international standards later.