John Roach & Sons

Between 1871 and 1885, the company was the largest shipbuilding firm in the United States, building more iron ships than its next two major competitors combined.

[1] As Roach's business empire expanded, a number of new companies were added as subsidiaries, the most important of which were the Delaware River Iron Ship Building and Engine Works in Chester, Pennsylvania, which was the main shipbuilding facility, and the Morgan Iron Works in New York.

John Roach & Sons remained the nation's largest shipbuilder from the establishment of the Delaware River Iron Shipbuilding and Engine Works in 1871 until 1885, building more tonnage of iron ships in these years than its next two major competitors combined.

Destined for the Oregon Railroad and Navigation Company, Columbia was the first ship to utilize a dynamo and was the first structure other than Thomas Edison's Menlo Park, New Jersey laboratory to use incandescent light bulbs.

The ships involved were the US Navy's first four steel-hulled warships, Atlanta, Boston, Chicago, and Dolphin.