The Railroad Redoubt was one of several redoubt

Redoubt

A redoubt is a fort or fort system usually consisting of an enclosed defensive emplacement outside a larger fort, usually relying on earthworks, though others are constructed of stone or brick. It is meant to protect soldiers outside the main defensive line and can be a permanent structure or a...

s, or small defensive earthworks, that were constructed during the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

 to protect the city of Vicksburg, Mississippi

Vicksburg, Mississippi

Vicksburg is a city in Warren County, Mississippi, United States. It is the only city in Warren County. It is located northwest of New Orleans on the Mississippi and Yazoo rivers, and due west of Jackson, the state capital. In 1900, 14,834 people lived in Vicksburg; in 1910, 20,814; in 1920,...

, from Union

Union Army

The Union Army was the land force that fought for the Union during the American Civil War. It was also known as the Federal Army, the U.S. Army, the Northern Army and the National Army...

 attack. It was so named because it was constructed along a major east-west railroad track into Vicksburg.

On May 22, 1863, the Union XIII Corps

XIII Corps (ACW)

XIII Corps was a corps of the Union Army during the American Civil War. It was first led by Ulysses S. Grant and later by John A. McClernand and Edward O.C. Ord...

, under the command of Major General

Major General

Major general or major-general is a military rank used in many countries. It is derived from the older rank of sergeant major general. A major general is a high-ranking officer, normally subordinate to the rank of lieutenant general and senior to the ranks of brigadier and brigadier general...

 John A. McClernand

John Alexander McClernand

John Alexander McClernand was an American lawyer and politician, and a Union general in the American Civil War. He was a classic case of the politician-in-uniform coming into conflict with career Army officers, graduates of the United States Military Academy. He was a prominent Democratic...

, attacked this portion of the Vicksburg defenses at 10:00a.m. Within the hour, several units were fighting in or near the ditch fronting the position.

One regiment, the 22nd Iowa Volunteer Infantry Regiment

22nd Iowa Volunteer Infantry Regiment

The 22nd Regiment Iowa Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.-Service:The 22nd Iowa Infantry was organized at Iowa City, Iowa and mustered in for three years of Federal service on September 9, 1862.The regiment was the only Union...

, with close support from the 21st Iowa Volunteer Infantry Regiment

21st Iowa Volunteer Infantry Regiment

The 21st Regiment Iowa Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.-Service:The 21st Iowa Infantry was organized at Dubuque, Iowa and mustered in for three years of Federal service on August 25, 1862.The regiment left Camp Franklin in...

, the 11th Wisconsin Volunteer Infantry Regiment

11th Wisconsin Volunteer Infantry Regiment

The 11th Regiment Wisconsin Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.-Service:The 11th Wisconsin was raised at Madison, Wisconsin and mustered into Federal service October 18, 1861....

 and the 77th Illinois Volunteer Infantry Regiment

77th Illinois Volunteer Infantry Regiment

The 77th Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.-Service:77th Regiment Illinois was organized at Peoria, Illinois and mustered into Federal service on September 3, 1862....

, exploited a breach in the Redoubt created by artillery fire, and about a dozen members of the 22nd Iowa entered the defenses at that point. The survivors from that group occupied a forward portion of the position for some hours. The breach was not successfully reinforced, and the attackers not killed or wounded, along with members of supporting units, were forced back as darkness fell.

In the end,the Confederate

Confederate States Army

The Confederate States Army was the army of the Confederate States of America while the Confederacy existed during the American Civil War. On February 8, 1861, delegates from the seven Deep South states which had already declared their secession from the United States of America adopted the...

 position held, bringing on the Siege of Vicksburg.