High Quality Content by WIKIPEDIA articles! John Lenthall (1807–1882) was an important American shipbuilder and naval architect in the mid-19th century. He was responsible for the construction and repair of United States Navy ships during the American Civil War (1861-1865), as well as in the years immediately before and after it. His career spanned the U.S. Navy`s transition from sail to steam propulsion and from wooden ships to ironclads, and in retirement he participated in early planning for an eventual steel navy.