Title: Vicksburg campaign
Content:  The Vicksburg campaign was a series of maneuvers and battles in the Western Theater of the American Civil War directed against Vicksburg, Mississippi, a fortress city that dominated the last Confederate-controlled section of the Mississippi River. The Union Army of the Tennessee under Major General Ulysses S. Grant gained control of the river by capturing this stronghold and defeating Lieutenant General John C. Pemberton's forces stationed there. The campaign consisted of many important naval operations, troop maneuvers, failed initiatives, and eleven distinct battles from December 26, 1862, to July 4, 1863. Military historians divide the campaign into two formal phases: operations against Vicksburg (December 1862 – January 1863) and Grant's operations against Vicksburg (March–July 1863). Grant initially planned a two-pronged approach 
Title: Mississippi in the American Civil War
Content:  Vicksburg was the site of the Battle of Vicksburg, a decisive victory as the Union forces gained control of the entire Mississippi River and cut the western states off. The battle consisted of a long siege, which was necessary because the town was on high ground, well fortified, and difficult to attack directly. The hardships of the civilians were extreme during the siege, with heavy shelling and starvation all around. Some 30,000 Confederates surrendered during the long campaign, but rather than being sent to prison camps, they were paroled and sent home until they could be exchanged for Union prisoners.
Title: Big Black River (Mississippi)
Content:  During the American Civil War, a pivotal battle between the Union and Confederate forces occurred along the Big Black River, culminating in the Siege of Vicksburg in 1863. Commanded by General Ulysses S. Grant, Union forces defeated Confederate troops under General John C. Pemberton at the Battle of Champion Hill. Grant chased Pemberton, who was headed toward Vicksburg. Pemberton left 5,000 troops to make a stand on both sides of the Big Black River after his Champion Hill defeat, while he withdrew with his main command to nearby Vicksburg.
Title: Siege of Vicksburg
Content:  The siege of Vicksburg (May 18 – July 4, 1863) was the final major military action in the Vicksburg campaign of the American Civil War. In a series of maneuvers, Union Maj. Gen. Ulysses S. Grant and his Army of the Tennessee crossed the Mississippi River and drove the Confederate Army of Mississippi, led by Lt. Gen. John C. Pemberton, into the defensive lines surrounding the fortress city of Vicksburg, Mississippi. Vicksburg was the last major Confederate stronghold on the Mississippi River; therefore, capturing it completed the second part of the Northern strategy, the Anaconda Plan. When two major assaults against the Confederate fortifications, on May 19 and 22, were repulsed with heavy casualties, Grant decided to besiege the city beginning on May 25. After holding out for more than forty days, with their supplies nearly gone, the garrison 
Title: Battle of Bayou Fourche
Content:  On July 4, 1863, Vicksburg, Mississippi – the Gibraltar of the Confederacy – fell. With the Mississippi River again, in President Abraham Lincoln's words, running "unvexed to the sea," Steele, commanding the "Arkansas Expedition," preceded from Helena on August 10 to lead the invasion of 12,000 troops west into Arkansas. Awakening to the distant rumble of artillery September 10, the citizens of Little Rock found themselves in the vortex of the conflict.
Title: Vicksburg Confederate order of battle
Content:  The following Confederate States Army units and commanders fought in the Siege of Vicksburg of the American Civil War. The Union order of battle is listed separately. Order of battle compiled from the army organization during the campaign.
Title: Vicksburg National Military Park
Content:  Vicksburg National Military Park preserves the site of the American Civil War Battle of Vicksburg, waged from March 29 to July 4, 1863. The park, located in Vicksburg, Mississippi (flanking the Mississippi River), also commemorates the greater Vicksburg Campaign which led up to the battle. Reconstructed forts and trenches evoke memories of the 47-day siege that ended in the surrender of the city. Victory here and at Port Hudson, farther south in Louisiana, gave the Union control of the Mississippi River.
Title: Battle of Milliken's Bend
Content:  The Battle of Milliken's Bend was fought on June 7, 1863, as part of the Vicksburg Campaign during the American Civil War. Major General Ulysses S. Grant of the Union Army had placed the strategic Mississippi River city of Vicksburg, Mississippi, under siege in mid-1863. Confederate leadership erroneously believed that Grant's supply line still ran through Milliken's Bend in Louisiana, and Major General Richard Taylor was tasked with disrupting it to aid the defense of Vicksburg. Taylor sent Brigadier General Henry E. McCulloch with a brigade of Texans to attack Milliken's Bend, which was held by a brigade of newly-recruited African American soldiers. McCulloch's attack struck early on the morning of June 7, and was initially successful in close-quarters fighting. Fire from the Union gunboat USS Choctaw halted the Confederate attack, and McCulloch later withdrew after the arrival of a second gunboat. The attempt to relieve Vicksburg was unsuccessful. One of the first actions in which African American soldiers fought, Milliken's Bend demonstrated the value of African American soldiers as part of the Union Army.
Title: Vicksburg, Mississippi
Content:  Vicksburg is a historic city in Warren County, Mississippi, United States. It is the county seat, and the population at the 2010 census was 23,856. Located on a high bluff on the east bank of the Mississippi River across from Louisiana, Vicksburg was built by French colonists in 1719, and the outpost withstood an attack from the native Natchez people. It was incorporated as Vicksburg in 1825 after Methodist missionary Newitt Vick. In the American Civil War, it was a key Confederate river-port, and its July 1863 surrender to Ulysses S. Grant, along with the concurrent Battle of Gettysburg, marked the turning-point of the war. The city is home to three large installations of the United States Army Corps of Engineers, which has often been involved in local flood control.
Title: Battle of Chickasaw Bayou
Content:  [[File:VicksburgCampaignDecember62March63.png|thumb|left|310px|Operations against Vicksburg and Grant's Bayou Operations. ]]Starting in November 1862, Maj. Gen. Ulysses S. Grant, commanding Union forces in Mississippi, undertook a campaign to capture the city of Vicksburg, high on the bluffs of the Mississippi River, one of two Confederate strong points (the other being Port Hudson, Louisiana) that denied the Union complete control of the Mississippi River. Grant split his 70,000-man army into two wings—one commanded by himself and one commanded by Maj. Gen. William T. Sherman. Sherman commanded the Right Wing, or XIII Corps, Army of the Tennessee, redesignated the XV Corps on December 22. His expeditionary force of 32,000 troops was organized into four divisions, commanded by Brig. Gens. Andrew J. Smith, Morgan L. Smith, 

Question: who fought in the battle of vicksburg?
Answer: Confederate States of America.