The wreck of the passenger ship Lyonnais, which sank in 1856, has been found about 200 miles off Massachusetts. A team from Atlantic Wreck Salvage discovered the ship using side-scan sonar and completing dives to gather information. Lyonnais was significant as one of the early steamships with an iron hull, used for transatlantic travel. The discovery enhances our understanding of maritime history and early shipbuilding techniques. The team plans to further explore the wreck and document the findings for publication.