May 22, 1863 – July 9, 1863
Also known as the Battle of Port Hudson, the Siege of Port Hudson was the longest siege in the history of American warfare.
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.
At the southern end of the river, U.S. Naval forces commanded by Flag Officer David G. Farragut shocked the Confederacy by subduing Forts Jackson and St. Philip, leading to the 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 of a 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 area where it joins the Mississippi.
In August 1862, Confederate General John C. Breckinridge led four thousand soldiers to Port Hudson, after failing in his attempt to retake Baton Rouge. After beginning improvements on the fortifications there, 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.
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 thirty thousand troops whom he helped recruit from the New England area. On December 14, 1862, one day after Gardner was named 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 sixteen thousand 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." In what was supposed to be a coordinated operation, Banks was to march a force of nearly ten thousand soldiers upriver and launch a diversionary land attack against Port Hudson. Meanwhile, Farragut would try to navigate his Gulf Squadron of seven boats past the distracted Confederate batteries overlooking the river in an attempt 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 managed to pass upriver to harass Confederate operations between Port Hudson and Vicksburg. Banks, meanwhile moved back downriver and requested reinforcements, convinced that his army of thirty to forty thousand soldiers was outmanned by the garrison at Port Hudson.
May 27 Assault
By May, Banks was prepared 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's torpidity 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 quickly the garrison at Port Hudson 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 they were needed. Despite being outnumbered nearly four to one, Gardner's troops easily repulsed the Union onslaught. When Banks finally called off the attacks at the end of the day, he had suffered nearly two thousand 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 were called upon to perform in a meaningful combat situation. Suffering nearly six hundred casualties, the First and Third Louisiana Native Guards, which consisted of an amalgam of free blacks from New Orleans and former slaves, demonstrated that black soldiers could perform as effectively as whites when facing the perils of war.
The disastrous outcome of the May 27 assault tested Banks's resolve. Unwilling to risk another failure on the same scale, Banks decided to institute 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's 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's 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 second 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 due to heatstroke and exposure to tropical disease.
With no supplies coming into Port Hudson, conditions were worse on the Confederate side. Gardner's troops were reduced to 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 of 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 from his troops would be pointless. Thus, he agreed to surrender the garrison at Port Hudson, giving the Union complete control of the Mississippi River. The Confederates had 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 five thousand Federal soldiers were wounded or killed, while another four thousand men were victims of heat stroke or disease. Of the 7,500 Confederate defenders, nearly two hundred were killed, two hundred died from disease, and three hundred to four hundred more were wounded seriously enough to be hospitalized.
Following the surrender, Banks paroled all of the enlisted men. They were allowed to return to their homes with the stipulation that they not take up arms against the Union again. The 405 Confederate officers at Port Hudson were imprisoned and sent 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 split the Confederacy.
No Ohio units participated in the Siege of Port Hudson.