This blue stock certificate from SeaTrain Lines Incorporated, issued in 1951, cancelled, features a vignette of a man in front of a train and ship and is registered in Delaware.

SeaTrain Lines, officially known as the Over-Seas Shipping Company, was a pioneering shipping and transportation company operating in the Americas and trans-Pacific regions. The company began intermodal freight transport in December 1928 by shipping entire loaded railroad freight cars between the United States and Cuba. The specially designed ship Seatrain, built in England, was followed by two larger ships in 1932 and two more in 1939. By the onset of World War II, SeaTrain was operating five ships, which became crucial for the war effort and inspired the design of fifty new military ships.

SeaTrain Lines utilized innovative loading systems that allowed entire railroad cars to be loaded onto ships, significantly reducing loading and unloading times. This method was a precursor to modern container shipping, which became widespread in the late 1950s. Throughout its history, SeaTrain expanded its fleet and operations, but faced financial difficulties in the 1970s due to the rise of containerized shipping. The company eventually filed for bankruptcy in 1981 and ceased operations.

SeaTrain was also notable for its Seamobile intermodal cargo container service introduced in 1958, and its pioneering coast-to-coast land bridge rail container service established in 1972. Despite its innovative contributions to shipping, SeaTrain's ventures into shipbuilding and the high costs associated with the oil crises of the 1970s contributed to its financial struggles.