John Ericsson (1803‒89) was an inventor and engineer whose innovations revolutionized naval warfare. In 1826 he emigrated from his native Sweden to Great Britain, where in 1836 he made significant improvements to the screw propeller. He moved to the United States in 1839. He designed the USS Princeton, the first steam-powered ship with engines and boilers entirely below the waterline. His most famous ship design was for the ironclad USS Monitor, which was completed in 1861 and fought the ironclad Merrimack (sunk April 1861, raised, reconstructed, and recommissioned as the Confederate States Ship [CSS] Virginia in February 1862) to a standoff at the Battle of Hampton Roads (March 8‒9, 1862). The image is from an album of mostly Civil War-era portraits by the famous American photographer Matthew Brady (circa 1823‒96) that belonged to Emperor Pedro II of Brazil (1825‒91), a collector of photography as well as a photographer himself. The album was a gift to the emperor from Edward Anthony (1818‒88), another early American photographer who, in partnership with his brother, owned a company that in the 1850s became the leading seller of photographic supplies in the United States. Dom Pedro may have acquired the album during a trip to the United States in 1876 when he, along with President Ulysses S. Grant, opened the Centennial Exposition in Philadelphia. Brady was born in upstate New York, the son of immigrants from Ireland. Best known for his photographs documenting the battles of the American Civil War, he began his career in 1844 when he opened a daguerreotype portrait studio at the corner of Broadway and Fulton Streets in New York City. Over the course of the next several decades, Brady produced portraits of leading American public figures, many of which were published as engravings in magazines and newspapers. In 1858 he opened a branch in Washington, DC. The album, which also contains a small number of non-photographic prints, is part of the Thereza Christina Maria Collection at the National Library of Brazil. The collection is composed of 21,742 photos assembled by Emperor Pedro II throughout his life and donated by him to the national library. The collection covers a wide variety of subjects. It documents the achievements of Brazil and Brazilians in the 19th century and also includes many photographs of Europe, Africa, and North America.