American Civil War: Clearing the Mississippi

Back: Invading the North

The Mississippi had been the most important transport link in the United States until just before the outbreak of the civil war. By 1861, the new railway network had reduced the importance of river traffic, especially from what is now the mid-west (then considered to be the north west). However, Chicago merchants who had depended on the river for their access to the outside world for generations were to take some time to realise this. Control of the Mississippi was seen as essential by both sides.

A quick look at a map will show you that roughly half of the Confederacy was to the west of the Mississippi River. However, this was a sparsely inhabited area, contributing only 20% of the free population of the Confederacy (1,122,260 out of 5,582,222 according to the 1860 census. Most of these people lived in the two states bordering the Mississippi, Arkansas and Louisiana. In Louisiana, nearly half of the free population lived in New Orleans, the biggest city in the Confederacy. The Mississippi was important because of the areas it flowed through, not because of those that Union control of the river would isolate (although the area did include the Confederacy’s one land border – that with Mexico, across which much war material was to flow).

At the start of the war, the Confederacy controlled the Mississippi from the northern border of Tennessee to the delta. The southernmost Union base was at Cairo, Illinois, where the Ohio and Mississippi Rivers meet. As the secession crisis developed, neutral Kentucky and chaotic Missouri lay between North and South.

The Mississippi was defended by a series of strong forts, aimed at preventing Union ships from using the river. The Confederates were also to be aided by the terrain around the river, often very wet and almost impassable to Union armies, especially early in the war.

Concern about the Mississippi in Kentucky led the Confederate commander in the area (Bishop Leonidas Polk) to send an army to Columbus, Kentucky at the start of September. While his guns did threaten any Union shipping on the river, his action sent Kentucky firmly into the Union camp. As well as opening up the Tennessee and Cumberland Rivers to Union attack, this meant that the position at Columbus was vulnerable.

Confederate concerns had been premature. The Union commander at Cairo, U.S. Grant, did not yet have the troops or the backing to launch any serious campaign, and when he did it was to be along the Cumberland and Tennessee Rivers. However, Polk’s presence did provide Grant with his first battle of the war, during a raid down the river (Belmont, 7 November 1861).

Polk’s forward position at Columbus had to be abandoned as a result of Grant’s campaign along the Tennessee and Cumberland Rivers in early 1862. The new Confederate front line was near the Tennessee border, centred on New Madrid and Island No. 10 (since eroded away), where the Confederates had placed 52 guns that they hoped would command the river. Similar strong fortifications had been built near the mouth of the Mississippi, where they provided the main defences for New Orleans. So confident were the Confederates that these forts would prevent any Union attack that they moved most of the troops based around New Orleans north to help in the campaign that was to end in defeat at Shiloh (6-7 April 1862).

April 1862 was a bad month for Confederate hopes on the Mississippi. General John Pope had captured New Madrid on 13 March. Now he moved against Island No. 10. He bypassed the Confederate strong point by digging a canal across a bend in the Mississippi. Now the Union fleet played a part, running their gunboats past the guns and allowing Pope to transport his men across to the Tennessee shore. On 7 April the defenders of Island No. 10 were forced to surrender.

Meanwhile, the Confederacy was about to suffer a much greater blow far to the south. Most of the best defenders of New Orleans had been sent north. Behind them they left 3,000 militia and a fleet of gunboats. They took this risk because they were confident that Fort Jackson and Fort St. Philip, seventy-five miles down river from New Orleans, would be able to sink any invading fleet.

If they had only faced the sailing ships that such forts had been designed to defeat after the war of 1812, then their 126 guns might well have proved enough, but time had moved on (in any case, skilled naval commanders had often overcome land based defences in earlier conflicts).

New Orleans’s fortifications were not the only connection to the War of 1812. Flag-Officer David G. Farragut, commander of the Union expedition, first joined the navy aged nine, just in time to fight in that war. Farragut was an example of Lincoln’s willingness to employ loyal Southerners. Tennessee born and married to a Virginian, Farragut was not about to desert his country.

He was just the right person for the attack on New Orleans. The mouth of the Mississippi was too shallow for large warships, so his fleet contained sloops, gunboats and schooners, smaller ships with smaller drafts, supported by 15,000 troops. At first he used mortar ships to bombard the Confederate forts, but after six days it was clear that the mortars weren’t working, and on 24 April Farragut steamed his fleet past the forts. Thirteen of seventeen ships ran the gauntlet successfully. The next day, Farragut’s fleet anchored off the now undefended New Orleans. There then following a comic-opera scene – no one could be found willing to surrender the city. Finally, on 29 April, Farragut got tired of waiting, and occupied the city’s main buildings (a desire to take the surrender before the army arrived may also have played a part).

Having lost their biggest city, the Confederates were about to lose their fifth as well, although not after putting up a rather better fight. After Shiloh, Memphis was threatened by a Union army to the east and by a fleet on the Mississippi. The city was defended by yet another fort (Fort Pillow, 50 miles upriver), but this time the fort’s guns were supported by a fleet on the river. This fleet was made up of converted river steamboats. The American Civil War saw a brief resurgence of ramming as a naval tactic. Steam power had increased the manoeuvrability and power of warships to the point where a determined attacker could very often inflict a great deal of damage (soon after this, naval gunnery increased in power and range, and the ram disappeared again).

The Confederate River Defence Fleet contained eight rams. Cotton bales provided them with light but effective armour. On 10 May this fleet attacked the Union gunboats bombarding Fort Pillow (Battle of Blum Run Bend), sinking two of the gunboats, and convincing the captain of the River Fleet that Memphis was safe.

What he failed to take into account was that the Union could also build rams. Under the command of their designer, Charles Ellet, a combined force of rams and ironclad gunboats attacked the Confederate fleet at Memphis. On 6 June, in front of a crowd of locals expecting to see their fleet win a crushing victory, Ellet’s fleet destroyed the Confederate fleet and captured the city.

Just over nine months after Polk had moved to secure the Mississippi in Kentucky, Confederate control of the river was reduced to the 200 miles between Vicksburg, Mississippi and Port Hudson, Louisiana (although these two locations are roughly 100 miles apart, the Mississippi’s endless s-bends account for the doubling of distance. Despite confident expectations, these last Confederate strongholds were to hold out for another year.

The first Union attempt to capture Vicksburg demonstrated their new dominance along the rest of the river. Farragut’s fleet from New Orleans sailed north, while the fleet from Memphis sailed south. The two fleets met at Vicksburg at the end of June 1862, but found the town already too well fortified for them to take. 200 feet above the river, the town was not vulnerable to the fleet’s guns, and the small army that Farragut had been able to transport was not big enough to threaten the defenders. When the water level started to fall, the two Union fleets went their separate ways.

The task of capturing Vicksburg now fell to Grant. On the appointment of Halleck as General-in-Chief, Grant had given command of the Department of the Tennessee (western Tennessee, Kentucky and Union occupied Mississippi). He concentrated enough of his available troops to attempt an overland attack on Vicksburg, and in December started south along the Mississippi Central Railroad, while a secondary force under Sherman headed along the river.

The railroad turned out to be Grant’s main weakness. Fifty miles east of the river, for 200 miles it ran through strongly Confederate areas of Mississippi. It was very vulnerable to Confederate cavalry raids. On 19 December Nathan Forest’s cavalry attacked the line near Jackson, Tennessee, cutting Grant’s supply line near the start. On 20 December an entire Confederate Cavalry Division captured Grant’s main supply depot at Holly Springs in northern Mississippi, capturing 1,500 men and a huge amount of supplies. Grant was forced to return north, abandoning his first attempt on Vicksburg. It was on this retreat that Grant first realised just how much food an army could forage in hostile territory – cut off from his supplies, his army was able to find two months worth of supplies without difficulty.

Tragically, Grant was unable to get the news of his retreat to Sherman in time to cancel the attack from the river. Sherman landed his troops up the Kazoo River, north of Vicksburg. His 32,000 men struggled across the swampy Chickasaw Bayou and attempted to attack the 14,000 dug-in Confederates on the Walnut Hills. The attack was a total failure – Sherman suffered 1,776 casualties while inflicted a mere 207 before being forced to withdraw back up the river.

Dispiriting though this setback was, the advantage was still with Grant. He now joined Sherman at Milliken’s Bend, just upriver from the city. His problem now was how to get his army across the river south of Vicksburg. He already controlled the east bank north of Vicksburg and the west bank opposite the city. His problem was that the area he controlled was almost entirely waterlogged. In contrast, Vicksburg was built on the high ground that marked the eastern edge of the Mississippi River’s flood plain.

Over the winter of 1862-3 Grant tried several different routes around Vicksburg. On the western bank he attempted several massive canal building projects, none of which worked. On the eastern bank two separate expeditions came to grief in the tangled swamps north of Vicksburg. Public opinion in the north started to turn against Grant, eventually forcing Lincoln to send Charles A. Dana, an assistant secretary of war, to investigate what was happening around Vicksburg. Dana was immediately impressed by Grant, and sent a stream of positive reports back to Lincoln, who in any case was already a fan of Grant, who had won many of the most significant Union victories of the war so far.

In contrast to the clear command structure on the Union side, the Confederate defenders of Vicksburg suffered from a confused command structure and a lack of any clear plan. The western Confederacy had been split into a series of military departments, each entirely self contained. On 24 November 1862 President Davies had placed General Joseph E. Johnston in charge of a Department of the West, but how much authority he wielded was never entirely clear, especially as Davies continued to issue orders directly to the departments. In Vicksburg the defence was commanded by General John Pemberton, a Southern by marriage only. In the campaign that was to come, Pemberton’s conviction that his key responsibility was to defend Vicksburg was to make Grant’s job much easier.

When the weather began to improve in the spring on 1863, Grant launched what was probably his most successful campaign. On his retreat through Mississippi in the previous December, Grant had learnt just how much food an army could find in any populated area. He now decided to take advantage of that and break loose from his supply chain. He planned to march his army down the western bank of the Mississippi while the navy ran past the guns of Vicksburg. Once below the city, his army would be ferried across the river to dry ground south of Vicksburg, from where he would be able to launch a campaign unhindered by the swamps of the Mississippi valley.

This was quite a gamble. If Johnston and Pemberton had combined their armies, they would have had more troops than Grant and would have been operating on home ground. It was possible that Grant’s gamble could have seen his army cut off and besieged south of Vicksburg. Luckily for Grant, Pemberton had not yet realised that the best way to secure Vicksburg would be to destroy Grant. He was concerned that if he moved most of his army out of the city, it could easily fall to even a small Union force. What he seems not to have realised was that if the combined Confederate armies had defeated Grant then that small Union force could be expelled with ease, while if the Confederate armies were defeated one by one, then Vicksburg would inevitably fall to Grant’s army.

Grant’s first gamble paid off. Showing a very poor sense of timing, the citizens of Vicksburg were so convinced that Grant was retreating to Memphis that on 16 April they held a gala ball to celebrate the lifting of the Union threat. As the ball was in full swing, the celebrations were interrupted by gunfire from the guns overlooking the Mississippi. The Union fleet was running the gauntlet. That night eight gunboats and two transports got past the guns of Vicksburg. By the end of the month, Grant had two thirds of his army and his fleet thirty miles south of Vicksburg.

He still had to cross the river. If he had concentrated his scattered men, Pemberton could have opposed Grant with a similar sized army, forcing Grant to make an opposed crossing of the Mississippi. However, Grant launched two diversions that succeeding so well that Grant was able to cross the river unopposed on 30 April.

The first of these diversions was a cavalry raid, led by Colonel Benjamin Grierson, that crossed 600 miles of the Confederate heartland of Mississippi before reaching Union held territory at Baton Rouge. This was probably the most impressive cavalry raid of the war. Grierson only lost 15 out of his 1,700 men during his sixteen day raid (17 April-12 May), and had pulled Pemberton’s cavalry away from the Vicksburg area.

The second diversion was on a larger scale – one third of Grant’s army, Sherman’s Fifteenth Corp, was sent to threaten the northern defences of Vicksburg. This diversion caused the recall of 3,000 men who had been sent south. Another 6,000 Confederates were based at Grand Gulf, ten miles north of Grant’s landing point. This position had been bombarded by the Union gunboats, and had been Grant’s first choice of landing point.

Once across the river, Grant quickly dealt with these 6,000 men (Battle of Port Gibson, 1 May). Grant was now faced with two enemies – Pemberton at Vicksburg and Johnston at Jackson, the state capitol, 40 miles inland. He decided to move east to deal with Johnston first. On 12 May his vanguard defeated a small Confederate force at Raymond, and then on 14 May drove Johnston out of Jackson.

Johnston was forced to flee north. He now ordered Pemberton to join him east of Vicksburg in the hope that their combined armies could defeat Grant. Unfortunately, Pemberton had send 20,000 of his men south, expecting to find Grant’s supply lines. Sadly for him, there were none, and when he turned north on 15 May he found Grant’s army in his way. At Champion’s Hill (16 May), Pemberton lost 3,800 men and his army split. Most of it reached Big Black River while one division was cut off and headed away towards Johnston. At Big Black River (17 May), Pemberton suffered another defeat, while waiting for his missing division, and was forced back into Vicksburg.

Grant made two quick attempts to capture Vicksburg by assault. The first, on 19 May, could only succeed if Pemberton’s army was badly demoralised. A second, on 22 May, was better prepared, but was still thrown back by the first class defences constructed over the last seven months. Grant now settled down to conduct a formal siege, while the Confederates tried to decide how to respond.

Although Johnston was soon able to build up a force 30,000 strong to the east, the only real Confederate action came from the west. A division from the Army of Louisina attempted to capture Grant’s camp at Milliken Bend (7 June), and was repulsed by two new regiments of black soldiers. The Confederate attack was marred by the probable murder of several captured soldiers. Meanwhile, Johnston refused to move. His army was probably not ever going to be able to dislodge Grant by itself, but if his 30,000 had combined with a sortie from the 27,000 inside Vicksburg, they might have had some success. Johnston appears to have been averse to risk taking through his military career. He was to take much of the blame for the fall of Vicksburg.

That blame was to be shared by Pemberton, partly because of his Yankee birth. Whatever his faults before the siege, the eventual surrender was not his fault. By the start of July, food was running out and it was increasingly clear that Johnston was not coming. Finally, on 28 June Pemberton had received an anonymous note from the men pleading for surrender before the army deserted away. His subordinates confirmed the state of the men on 1 July, ruling out any attempt at a breakout. On 3 July Grant and Pemberton met between the lines, and arranged for the surrender of Vicksburg.

Grant’s first surrender terms were similar to his famous ‘unconditional surrender’ terms at Fort Donalson. However, he quickly changed his mind, and offered the Confederate garrison their parole, allowing them to return to their homes as long as they agreed not to fight against the Union. He had two reasons for this. First, the garrison numbered 2,166 officers and 27,230 men when it surrendered. To ship 30,000 men back north would have strained Grant’s resources. Second, he felt that 30,000 demoralised ex-Confederate soldiers spread around the southern states would do far more damage to southern morale than if they were in captivity. Accordingly, after their formal surrender on 4 July, the Confederate Army of Vicksburg simply dissolved.

The surrender of Vicksburg left Port Hudson as the only Confederate strongpoint on the Mississippi. When the news from Vicksburg reached the besieged garrison they surrendered (9 July). One week later the first merchant ship completed the trip from St. Louis to New Orleans. In Lincoln’s words, ‘The Father of Waters again goes unvexed to the sea’.

The capture of Vicksburg split the Confederacy in two. No more supplies would be coming to Lee’s armies from Texas or across the Mexican border. Grant demonstrated his skills as a probably the most able general of the war. When Lincoln once again needed to find a new General in Chief at the start of 1864, he knew where to look. Grant’s successes in the west prepared the way for his monumental clash with Lee in Virginia.

Next: Tennessee and Kentucky

A.C.W. Home Page | A.C.W. Subject Index | A.C.W. Books | A.C.W. Links

Battle Cry of FreedomBattle Cry of Freedom, James M. McPherson, OUP, 1988, 944 pages. One of the best single volume accounts of the Civil War era, taking in the decade before the war before moving on to the conflict itself. McPherson covers the military events of the war well, while also including good sections on politics North and South. [see more]
cover cover cover
How to cite this article: Rickard, J (1 May 2006), American Civil War: Clearing the Mississippi ,

Help - F.A.Q. - Contact Us - Search - Recent - About Us - Privacy