Also known as the Battle of Port Hudson, the Siege of Port Hudson was the longest siege in the history of American warfare.
Northern Mississippi River
From the onset of the American Civil War, seizing control of the Mississippi River was a primary goal of Union forces operating in the Western Theater. In February 1862, troops commanded by Brigadier General Ulysses S. Grant opened the door by capturing Fort Henry, on the Tennessee River, and Fort Donelson, on the Cumberland River. As federal forces pushed south after their victories at the Battle of Shiloh (April 6-7, 1862) and the Siege of Corinth (April 29 to May 30, 1862), Rebel troops evacuated Memphis, Tennessee and civilian authorities surrendered the city to Union occupation on June 6, 1862.
Southern Mississippi River
At the southern end of the river, U.S. Naval forces commanded by Flag Officer David G. Farragut shocked the Confederacy by subduing Fort Jackson and Fort St. Philip, leading to the federal occupation of New Orleans by Major General Benjamin F. Butler’s Army of the Gulf on May 1, 1862. Butler’s army then marched north and occupied Baton Rouge on May 29. Farragut’s and Butler’s unexpectedly easy conquests forced Louisiana state officials to withdraw to Opelousas and then to Shreveport.
In less than one-half-year, Confederate control of the mighty river had dwindled to a stretch of roughly two hundred miles from southern Mississippi, at Vicksburg, to northern Louisiana, at Shreveport. Between those two points, the Red River flows into the Mississippi River. Because the Red River served as a vital artery for supplies and troops from the West, it was imperative for the Confederacy to maintain control of the area where it joins the Mississippi.
In August 1862, Confederate General John C. Breckinridge led 4,000 soldiers to Port Hudson, after failing in his attempt to retake Baton Rouge. After beginning improvements on the fortifications at Port Hudson, Breckinridge departed, leaving behind nearly 1,500 men, commanded by General Daniel Ruggles, to continue the work. On December 13, 1862, Confederate officials ordered Major General Franklin Gardner to assume command of the works and of the garrison at Port Hudson. A gifted engineer and project director, Gardner arrived at Port Hudson on December 27, 1862, and immediately set about supervising the construction of significant defensive improvements to the post.
Banks Replaces Butler
Near the same time that the Confederacy was changing commanders at Port Hudson, the Union was changing military leadership in Louisiana. On November 9, 1862, the U.S. War Department issued General Order No. 184, naming Major General Nathaniel P. Banks to replace Benjamin F. Butler as commander of the Department and Army of the Gulf. The U.S. Army General-in-Chief Henry Halleck made it clear to Banks that President Lincoln “regards the opening of the Mississippi River as the first and most important of all our military and naval operations, and it is hoped that you will not lose a moment in accomplishing it.” Banks set out for Louisiana with 30,000 troops whom he helped recruit from the New England area. On December 14, 1862, one day after officials named Gardner the commander of Port Hudson, Banks relieved Butler at New Orleans.
Despite Halleck’s admonition, Banks spent his first few months in command, focused on easing tensions in New Orleans attributed to Butler’s harsh occupation policies. Meanwhile, the number of Confederate troops at Port Hudson grew to nearly 16,000 men by March 1863.
March 14 Assault
After months of planning, Banks made his first attempt to fulfill President Lincoln’s goal of “opening the Mississippi River.” As part of a coordinated operation, Banks marched a force of nearly 10,000 soldiers upriver to launch a diversionary land attack against Port Hudson. Meanwhile, Farragut tried to navigate his Gulf Squadron of seven boats past the distracted Confederate batteries overlooking the river while attempting to reach the mouth of the Red River.
On March 14, 1863, Farragut attempted to pass the Rebel stronghold, but inexplicably, Banks troops failed to attack. Instead, Rebel gunners were free to concentrate their efforts against Farragut’s naval squadron. In the maelstrom that followed, Rebel artillerists sank one ship and damaged four others so badly that they had to retreat downstream. Only Farragut’s flagship, the Hartford, and its escort passed upriver to harass Confederate operations between Port Hudson and Vicksburg. Meanwhile, Banks moved back downriver and requested reinforcements, convinced that the Rebel garrison at Port Hudson outnumbered forces his army of 30,000 to 40,000 soldiers.
May 27 Assault
By May, Banks was ready to try again. By that time, the redeployment of Rebel troops to Vicksburg, where General Grant had begun operations, had reduced the size of the garrison at Port Hudson to approximately 7,500 soldiers. Still, Banks’ idleness had bought Gardner time to resupply and further to fortify his position, making Port Hudson an even more formidable target.
By May 27, 1863, Banks had moved five divisions into position to surround and to assault Port Hudson by land. Three divisions advanced from the northwest, and two divisions advanced from the south. Banks planned to overwhelm the garrison at Port Hudson quickly and then to proceed north to assist Grant’s investment of Vicksburg.
What followed instead was a disjointed Union assault that unfolded in piecemeal fashion. The uncoordinated nature of the federal assault enabled Gardner to shift men to various parts of his defenses as required. Despite being outnumbered nearly four-to-one, Gardner’s troops easily repulsed the Union onslaught. When Banks finally called off the attacks, he had suffered nearly 2,000 casualties compared to Gardner’s 235.
The only positive aspect of the May 27 assault was that it marked the first time during the Civil War that black soldiers served in a meaningful combat role. Suffering nearly 600 casualties, the 1st and 3rd Louisiana Native Guards, which comprised an amalgam of free blacks from New Orleans and former slaves, proved that black soldiers could perform as effectively as whites when facing the perils of war.
Siege of Port Hudson
The disastrous outcome of the May 27 assault tested Banks’ resolve. Unwilling to risk another failure on the same scale, Banks began a siege. Within four days, Banks had his engineers excavating trenches and erecting fortifications around the perimeter of Port Hudson. To make sure Gardner’s troops remained trapped, Banks brought up an additional nine regiments to man the new entrenchments. By June 1, Banks’ cannoneers, complemented by naval gunners on the river, began shelling the cornered Rebels.
June 14 Assault
For the next two weeks, the Confederates held out as Banks’ patience wore thin. On June 14, he again attempted to storm Port Hudson. The second assault produced results similar to the May 27 debacle. Banks suffered another 1,700 casualties, including 203 killed, compared to fewer than fifty Confederate casualties.
Following the failed assault, Banks continued to invest Port Hudson. Throughout the siege, both sides suffered considerably. Unprepared for a lengthy investment, Banks’ soldiers were ill-provisioned, and they suffered immeasurably from the intense Louisiana summer heat. Thousands of Union soldiers were hospitalized because of heatstroke and exposure to tropical diseases.
With no supplies coming into Port Hudson, conditions grew bad on the Confederate side. Gardner’s troops began eating nearly anything that they could get their hands on, including horses, mules, dogs, cats, and even rats. Constantly subjected to deadly shelling and sniper fire, morale grew increasingly low.
Despite all the deprivations, the Confederate defenders of Port Hudson continued to hold out, prompting Banks to plan for a third assault, scheduled for July 11. Two days before the planned offensive, word reached Gardner that the Rebel forces at Vicksburg had surrendered to Grant on July 4. Gardner realized that any further resistance would be pointless. Thus, he agreed to surrender the garrison at Port Hudson, giving the Union complete control of the Mississippi River. The Confederates held out for forty-eight days, making the Siege of Port Hudson the longest siege in American history.
Casualties of the siege and accompanying assaults were high, especially on the Union side. Approximately 5,000 Federal soldiers were wounded or killed, while another 4,000 men were victims of heatstroke or diseases. Of the 7,500 Confederate defenders, nearly 200 were killed, 200 died from disease, and 300-400 more were wounded seriously enough to be hospitalized.
Following the surrender, Banks paroled all the enlisted men. He allowed them to return to their homes with the stipulation that they would not take up arms against the Union again. Banks imprisoned the 405 Confederate officers at Port Hudson before sending them north. Many of them ended up at Johnson’s Island Prison Camp near Marblehead, Ohio.
Banks’ victory was a significant milepost in the Civil War. Coupled with Grant’s success at Vicksburg, the subjugation of Port Hudson established Union control of the Mississippi River and divided the Confederacy.