Seatrain was established to specialize in carrying loaded railroad cars in the U.S. Atlantic coastwise trade and between the US and Cuba. It was a considerable success and soon expanded into other geographic regions and other areas of shipping such as tankers. The loss of the Cuba trade after the Cuban Revolution hurt the company, as did competition from the railroads. As a result, Seatrain decided to focus on the tanker trade and was one of the most innovative companies in the business, fitting the supertanker Manhattan as an icebreaker and using it to open the Northwest Passage to ship Alaska oil directly to the US east coast. Although technically successful, the venture was not profitable, so Seatrain instead decided to focus on containerships. It pioneered the "landbridge" concept across the United States, cutting 10 days off travel time from Europe to the Far East, and was in position to become a dominant force in the industry despite a heavy debt burden. However, its owners decided to get into the shipbuilding business, which sucked off more resources, then to diversify into oil and coal  production, and eventually drove it into bankruptcy. The company was finally liquidated in 1982.

Source: fotw.fivestarflags.com