Cyrus Field, American businessman and financier, set his sights on laying the first transatlantic underwater telegraph cable after having been contacted by Frederic Newton Gisborne who attempted to connect St. John's, Newfoundland to New York City, but failed due to lack of funding.

[2] After inquiring about the feasibility of a transatlantic underwater cable to Lieutenant Matthew Fontaine Maury of the U.S. Navy,[3] Field formed an agreement with the Englishmen John Watkins Brett and Charles Tilston Bright to create the Atlantic Telegraph Company.

This attempt was completed on August 5, 1858 and was celebrated by an exchange of messages between Queen Victoria of England and President Buchanan of the United States using the new cable line.

[5] When a second cable, under Thomson's supervision, was proposed, the Admiralty lent the hulks of HMS Amethyst and HMS Iris to the Company in 1864, both ships were then extensively modified in 1865 for ferrying the Atlantic cable from the works at Enderby's wharf, in East Greenwich, London, to Great Eastern at her Sheerness mooring.

Amethyst and Iris transferred the 2500 miles (4022 km) of cable to Great Eastern, beginning in February 1865,[6] an operation that took over three months.