The Siege of Vicksburg (May 18 – July 4, 1863) was the final major military action in the Vicksburg Campaign

Vicksburg Campaign

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 Maj. Gen....

 of 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...

. In a series of maneuvers, 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...

 Maj. Gen.

Major general (United States)

In the United States Army, United States Marine Corps, and United States Air Force, major general is a two-star general-officer rank, with the pay grade of O-8. Major general ranks above brigadier general and below lieutenant general...

 Ulysses S. Grant

Ulysses S. Grant

Ulysses S. Grant was the 18th President of the United States as well as military commander during the Civil War and post-war Reconstruction periods. Under Grant's command, the Union Army defeated the Confederate military and ended the Confederate States of America...

 and his Army of the Tennessee

Army of the Tennessee

The Army of the Tennessee was a Union army in the Western Theater of the American Civil War, named for the Tennessee River. It should not be confused with the similarly named Army of Tennessee, a Confederate army named after the State of Tennessee....

 crossed the Mississippi River and drove 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...

 army of Lt. Gen. John C. Pemberton

John C. Pemberton

John Clifford Pemberton , was a career United States Army officer who fought in the Seminole Wars and with distinction during the Mexican–American War. He also served as a Confederate general during the American Civil War, noted for his defeat and surrender in the critical Siege of Vicksburg in...

 into the defensive lines surrounding the fortress 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,...

.

When two major assaults (May 19 and May 22, 1863) against the Confederate fortifications were repulsed with heavy casualties, Grant decided to besiege the city beginning on May 25.