Joseph Hooker was an American Civil War general for the Union, chiefly remembered for his decisive defeat by Confederate General Robert E. Lee at the Battle of Chancellorsville in 1863.
The siege of Vicksburg was the final major military action in the Vicksburg campaign of the American Civil War. In a series of maneuvers, Union Major General Ulysses S. Grant and his Army of the Tennessee crossed the Mississippi River and drove the Confederate Army of Mississippi, led by Lieutenant General John C. Pemberton, into the defensive lines surrounding the fortress city of Vicksburg, Mississippi, leading to the successful siege and Confederate surrender.
Oliver Otis Howard was a career United States Army officer and a Union general in the Civil War. As a brigade commander in the Army of the Potomac, Howard lost his right arm while leading his men against Confederate forces at the Battle of Fair Oaks/Seven Pines in June 1862, an action which later earned him the Medal of Honor. As a corps commander, he suffered a major defeat at Chancellorsville and his performance was of question at Gettysburg in May and July 1863. However, he recovered from possible career setbacks as a successful corps and later army commander, commanding the Army of the Tennessee from July 27, 1864 until May 19, 1865 leading the army in the battles of Ezra Church, Battle of Jonesborough, Sherman's March to the Sea, and the Carolinas campaign in the Western Theater.
The Battle of Lookout Mountain also known as the Battle Above the Clouds was fought November 24, 1863, as part of the Chattanooga Campaign of the American Civil War. Union forces under Maj. Gen. Joseph Hooker assaulted Lookout Mountain, Chattanooga, Tennessee, and defeated Confederate forces commanded by Maj. Gen. Carter L. Stevenson. Lookout Mountain was one engagement in the Chattanooga battles between Maj. Gen. Ulysses S. Grant's Military Division of the Mississippi and the Confederate Army of Tennessee, commanded by Gen. Braxton Bragg. It drove in the Confederate left flank and allowed Hooker's men to assist in the Battle of Missionary Ridge the following day, which routed Bragg's army, lifting the siege of Union forces in Chattanooga, and opening the gateway into the Deep South.
The Army of the Tennessee was a Union army in the Western Theater of the American Civil War, named for the Tennessee River. A 2005 study of the army states that it "was present at most of the great battles that became turning points of the war—Fort Donelson, Vicksburg, and Atlanta" and "won the decisive battles in the decisive theater of the war."
Henry Warner Slocum Sr., was a Union general during the American Civil War and later served in the United States House of Representatives from New York. During the war, he was one of the youngest major generals in the Army and fought numerous major battles in the Eastern Theater and in Georgia and the Carolinas. While commanding a regiment, a brigade, a division, and a corps in the Army of the Potomac, he saw action at First Bull Run, the Peninsula Campaign, Harpers Ferry, South Mountain, Antietam, and Chancellorsville.
The Atlanta campaign was a series of battles fought in the Western Theater of the American Civil War throughout northwest Georgia and the area around Atlanta during the summer of 1864. Union Maj. Gen. William Tecumseh Sherman invaded Georgia from the vicinity of Chattanooga, Tennessee, beginning in May 1864, opposed by the Confederate general Joseph E. Johnston.
The Battle of Missionary Ridge, also known as the Battle of Chattanooga, was fought on November 25, 1863, as part of the Chattanooga campaign of the American Civil War. Following the Union victory in the Battle of Lookout Mountain on November 24, Union forces in the Military Division of the Mississippi under Maj. Gen. Ulysses S. Grant assaulted Missionary Ridge and defeated the Confederate Army of Tennessee, commanded by Gen. Braxton Bragg, forcing it to retreat to Georgia.
Army of the Mississippi was the name given to two Union armies that operated around the Mississippi River, both with short existences, during the American Civil War.
The XII Corps was a corps of the Union Army during the American Civil War.
The XVI Army Corps was a corps of the Union Army during the American Civil War. The corps rarely fought as a single unit, as its divisions were often scattered across the country.
XVII Corps was a corps of the Union Army during the American Civil War. It was organized December 18, 1862 as part of Ulysses S. Grant's Army of the Tennessee. It was most notably commanded by Maj. Gen. James B. McPherson and Maj. Gen. Francis P. Blair II, and served in the Western Theater.
Baron Adolph Wilhelm August Friedrich von Steinwehr was a German-Brunswick army officer who emigrated to the United States, became a geographer, cartographer, and author, and served as a Union general in the American Civil War.
Corps badges in the American Civil War were originally worn by soldiers of the Union Army on the top of their army forage cap (kepi), left side of the hat, or over their left breast. The idea is attributed to Maj. Gen. Philip Kearny, who ordered the men in his division to sew a two-inch square of red cloth on their hats to avoid confusion on the battlefield. This idea was adopted by Maj. Gen. Joseph Hooker after he assumed command of the Army of the Potomac, so any soldier could be identified at a distance.
The city of Atlanta, Georgia, in Fulton County, was an important rail and commercial center during the American Civil War. Although relatively small in population, the city became a critical point of contention during the Atlanta Campaign in 1864 when a powerful Union Army approached from Union-held Tennessee. The fall of Atlanta was a critical point in the Civil War, giving the North more confidence, and leading to the re-election of President Abraham Lincoln and the eventual dissolution of the Confederacy. The capture of the "Gate City of the South" was especially important for Lincoln as he was in a contentious election campaign against the Democratic opponent George B. McClellan.
The 13th Infantry Regiment is a United States Army infantry regiment whose battalions are currently tasked as basic training battalions.
The 46th Pennsylvania Volunteer Infantry was a Union Army regiment in the American Civil War. It served in both the Eastern and Western Theaters, most notably at the 1862 Battle of Cedar Mountain and during the 1864 Atlanta Campaign. During the war, the regiment lost 17% of its strength through combat losses and disease.
The 68th New York Infantry Regiment served in the Union Army during the American Civil War. Also known as the Cameron Rifles or the Second German Rifle Regiment, the men were mostly German immigrants. Organized in July 1861, three months after the outbreak of war, the 68th saw service in the Eastern and Western theaters.
The Chattanooga campaign was a series of maneuvers and battles in October and November 1863, during the American Civil War. Following the defeat of Maj. Gen. William S. Rosecrans's Union Army of the Cumberland at the Battle of Chickamauga in September, the Confederate Army of Tennessee under Gen. Braxton Bragg besieged Rosecrans and his men by occupying key high terrain around Chattanooga, Tennessee. Maj. Gen. Ulysses S. Grant was given command of Union forces in the West which was now consolidated under the Division of the Mississippi. Significant reinforcements also began to arrive with him in Chattanooga from Mississippi and the Eastern Theater. On October 18, Grant removed Rosecrans from command of the Army of the Cumberland and replaced him with Major General George Henry Thomas.
The following units and commanders fought in the Chattanooga–Ringgold campaign of the American Civil War on the Union side. The Confederate order of battle is shown separately. Order of battle compiled from the army organization during the campaign, the casualty returns and the reports.
United States of America 
