Joseph Hooker (1814‒79) was a Union general in the American Civil War. Born in Hadley, Massachusetts, he graduated from the United States Military Academy at West Point and served in the Mexican War (1846‒48). During the Civil War, he commanded a division in the Peninsular Campaign of 1862 and as a corps commander led the initial Union attacks at the Battle of Antietam. In January 1863 he replaced Ambrose Everett Burnside as commander of the Army of the Potomac, but he was relieved of his command by President Abraham Lincoln in June of that year after suffering a serious defeat at Chancellorsville. He later served under General Ulysses S. Grant in the western theater of operations and was with General William Tecumseh Sherman when he entered Atlanta in September 1864. His nickname was “Fighting Joe” Hooker. In this photograph, taken in 1861 or 1862, he is identified as a brigadier general. He was later promoted to major general. 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.