The Vicksburg Campaign (1863): Grant's Real Siege & Control of the Mississippi

Military History: The US Civil War

Chapter 7 · The Vicksburg Campaign (1863): Grant's Real Siege & Control of the Mississippi

Gettysburg (Chapter 6) gets most of the attention, but on the very next day, a thousand miles away, the Union won something arguably more important. Vicksburg, Mississippi, was the last major Confederate fortress on the Mississippi River. Taking it completed the river half of the Anaconda Plan (Chapter 4), split the Confederacy in two, and made Ulysses S. Grant the Union's leading general.

Why Vicksburg Was So Hard to Take

High Bluffs

The city stood on bluffs about 200 feet above a sharp bend in the river. Its heavy guns could fire on any ship passing below.

Swamps to the North

North of the city lay the Yazoo delta: rivers, bayous, and flooded forest that made moving an army almost impossible.

The Wrong Side of the River

Grant's army was on the western (Louisiana) bank and upriver. To attack, he had to get across the Mississippi and past the guns.

Phase One: Failure (December 1862 – March 1863)

26–29 December 1862 William T. Sherman's direct assault at Chickasaw Bayou, north of the city, is thrown back with heavy losses.
Winter 1863 Grant tries five different ways to get around the guns through the waterways: digging a canal across the river bend, and expeditions through bayous such as Yazoo Pass and Steele's Bayou. All of them fail.

Why the Failures Still Mattered Northern newspapers called for Grant's removal. But the failed expeditions kept his army busy through a wet winter, kept Confederate commanders guessing, and ruled out every easy option. Lincoln kept Grant. A later account says Lincoln had already defended him after the bloody battle of Shiloh in 1862 with the words "I can't spare this man; he fights" — a famous line, though it rests on one witness's memory.

Phase Two: The Gamble (April – May 1863)

Grant's new plan was risky: march his army south down the Louisiana bank, run the Navy's gunboats and transports downriver past Vicksburg's guns at night, and use them to ferry the army across the river well south of the city.

16–22 April 1863 Admiral David Dixon Porter's flotilla runs past the Vicksburg batteries at night. Despite heavy fire, almost every vessel gets through.
17 April – 2 May Grierson's Raid: Colonel Benjamin Grierson's Union cavalry rides hundreds of miles through Mississippi, tearing up railroads and drawing Confederate attention away from the river.
29–30 April Grant's army crosses the Mississippi at Bruinsburg, south of Vicksburg, in one of the largest river crossings in American military history up to then.

Five Battles in Seventeen Days

Instead of heading straight north to Vicksburg, Grant first struck east toward the state capital, Jackson, to keep two Confederate forces from joining. In seventeen days he won five battles — Port Gibson, Raymond, Jackson, Champion Hill (16 May, the decisive one), and Big Black River Bridge — and drove the Confederate army under John C. Pemberton back inside Vicksburg's defences.

"Living Off the Land" — Partly True Grant is often said to have "cut loose" from his supply lines and fed his army entirely from the countryside. He did rely heavily on local food, livestock, and forage, which let him move fast. But he still ran wagon trains of ammunition and some rations along a road back to the river. It was a bold reduction of his supply line, not a complete abandonment of it — and Sherman would take the idea much further in Georgia (Chapter 8).

Phase Three: The Siege (18 May – 4 July 1863)

Grant tried two direct assaults on the city's defences, on 19 and 22 May. Both failed with heavy losses. He then settled into a formal siege, digging trenches ever closer to the Confederate lines and cutting the city off completely.

Soldiers Starving

By late June, half the Confederate garrison was sick with scurvy, malaria, or dysentery. Rations shrank, and there were reports of soldiers eating mules and even shoe leather.

Civilians in Caves

Under daily shelling from Union guns and gunboats, many of the city's residents dug caves into the hillsides and lived in them for weeks.

A Mine Under the Lines

On 25 June Union engineers exploded a large charge of gunpowder in a tunnel under a Confederate fort, the 3rd Louisiana Redan. Troops rushed into the crater but were driven back — a smaller version of a tactic that would fail more famously at Petersburg in 1864.

Milliken's Bend, 7 June 1863

Confederates attacked a Union supply post at Milliken's Bend, across the river, defended mostly by recently recruited Black regiments. After fierce hand-to-hand fighting, the defenders held with the help of gunboat fire. It was one of the first battles to show sceptical Northern commanders that Black troops would fight — a direct military result of the emancipation policy from Chapter 5.

The Surrender

On 4 July 1863 — the day after Pickett's Charge — Pemberton surrendered about 29,500 men. He chose the date partly in the hope that Grant would offer better terms on Independence Day. Grant paroled the prisoners rather than send them north, which saved him the huge task of moving and guarding them.

	Union (Grant)	Confederate
Casualties, whole campaign	About 10,100	More than 38,000, most of them the soldiers captured at the surrender

The Fourth of July Myth A popular story says Vicksburg refused to celebrate the Fourth of July for over 80 years, until the Second World War. It makes a neat symbol of lasting resentment — but records show large Independence Day celebrations in the city at least as early as 1907.

Why It Mattered

The River Is Open

When Port Hudson, Louisiana, the last Confederate position on the river, surrendered on 9 July, the whole Mississippi was in Union hands. Lincoln wrote that "the Father of Waters again goes unvexed to the sea."

The Confederacy Split

Texas, Arkansas, and most of Louisiana were cut off from the rest of the Confederacy, along with the cattle, horses, and supplies they had sent east.

Grant Rises

After another victory at Chattanooga in November 1863, Grant was promoted in March 1864 to lieutenant general and command of all Union armies. Chapter 9 follows him east to face Lee.

Gettysburg and Vicksburg Together Chapter 6's closing note asked whether Gettysburg was really the war's turning point. Many historians point to Vicksburg as the more decisive of the two: Gettysburg stopped an invasion, while Vicksburg took an entire army out of the war and permanently changed the map. What made July 1863 so important was that both happened at once.

Questions to Sit With

Grant failed repeatedly through the winter. What might have happened if Lincoln had given in to calls to remove him?

Why do you think Gettysburg is so much better remembered than Vicksburg, even though Vicksburg arguably did more to end the war?

Grant's plan depended on the Army and Navy working closely together. Where else in this course has that kind of cooperation decided a campaign?

Quick Reference — Chapter 7

Vicksburg's high bluffs, northern swamps, and position on the river made it the Confederacy's strongest river fortress
Chickasaw Bayou (December 1862) and five winter waterway attempts all failed
April 1863: Porter's gunboats ran the batteries, Grierson's Raid distracted the Confederates, and Grant crossed at Bruinsburg
Grant won five battles in seventeen days, including Champion Hill (16 May), relying heavily on local supplies
After failed assaults on 19 and 22 May, the siege lasted until 4 July; Black troops held at Milliken's Bend (7 June)
Pemberton surrendered about 29,500 men on 4 July 1863; Port Hudson fell on 9 July, opening the whole Mississippi
The Confederacy was split; Grant rose to command all Union armies in March 1864

What's Next

Chapter 8: Sherman's March to the Sea (1864): Real Total War Strategy.