William Cramp and Sons Ship and Engine Building Co. (1830-1927) was a respected Philadelphia shipbuilding firm founded by William Cramp (1807-1879). During the almost 100 years of its existence, the firm was commissioned to design and build ships for corporations, states, and nations. The company built over 500 vessels of many types, including battleships, sloops, yachts, caissons, cruisers, tugboats, barges, tenders, lighters, oil tankers, and passenger steamers. At the end of its existence, the firm even produced submarines.
The company was founded under the name William Cramp Shipbuilding Co., but once his sons began to take part in the firm's activities, the name was changed to the William Cramp and Sons Ship and Engine Building Co. in 1872.
At the time when most of the blueprints in Seward's collection were produced, the firm was operating under the leadership of William Cramp's son, Charles Henry Cramp (1828-1913), who started working with his father in 1846. During his tenure as president of the company, Charles oversaw the construction of about 200 vessels, most famously the U.S.S. "New Ironsides," which the firm built during the Civil War. The ship participated in the largest number of naval engagements during the Civil War of any other vessel, Union or Confederate.
During the time when the plans in Seward's collection were created, the shipbuilding industry underwent many changes, including the transition from wooden to iron and then steel vessels. Machinery, industrial organization, and naval architecture and construction were also the subjects of radical change. Many small shipbuilding companies were replaced by a few large corporations. As vessels grew larger and more complex, the plant and equipment infrastructure, as well as expenditures, grew along with them.
The firm managed to weather these changes until 1915, when the firm was purchased by the American Ship and Commerce Corporation and in 1919, a larger conglomerate absorbed it. In 1927, the shipbuilding branch of the conglomerate was discontinued. Shipbuilding operations recommenced in 1941, but after wartime contracts were completed in 1946, the shipyward ceased operations permanently.