American Civil War: Siege of Port Hudson

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Union guns during the Siege of Port Hudson. Photograph Courtesy of the National Archives & Records Administration

The Battle of Port Hudson lasted from May 22 to July 9, 1863, during the American Civil War (1861-1865) and saw Union troops final take control of the entirety of the Mississippi River. Having captured New Orleans and Memphis in early 1862, Union forces sought to open the Mississippi River and split the Confederacy in two. In an effort to prevent this from occurring, Confederate troops fortified key locations at Vicksburg, MS and Port Hudson, LA.

The capture of Vicksburg was tasked to Major General Ulysses S. Grant. Having already won victories at Fort Henry, Fort Donelson, and Shiloh, he began operations against Vicksburg in late 1862.

A New Commander

As Grant commenced his campaign against Vicksburg, the capture of Port Hudson was assigned to Major General Nathaniel Banks. The commander of the Department of the Gulf, Banks had taken command at New Orleans in December 1862 when he relieved Major General Benjamin Butler. Advancing in May 1863 in support of Grant's effort, his principal command was the large Union XIX Corps. This was comprised of four divisions led by Brigadier General Cuvier Grover, Brigadier General W. H. Emory, Major General C. C. Augur, and Brigadier General Thomas W. Sherman.

Port Hudson Prepares

The idea for fortifying Port Hudson came from General P.G.T. Beauregard in early 1862. Assessing defenses along the Mississippi, he felt that the town's commanding heights which overlooked a hairpin turn in the river provided the ideal location for batteries.

Additionally, the broken terrain outside of Port Hudson, which contained ravines, swamps, and woods, helped make the town extremely defensible. Design of Port Hudson's defenses was overseen by Captain James Nocquet who served on the staff of Major General John C. Breckinridge.

Construction was initially directed by Brigadier General Daniel Ruggles and continued by Brigadier General William Nelson Rector Beall.

Work pressed on through the year though delays ensued as Port Hudson had no rail access. On December 27, Major General Franklin Gardner arrived to take command of the garrison. He quickly worked to enhance the fortifications and constructed roads to facilitate troop movement. Gardner's efforts first paid dividends in March 1863 when the majority of Rear Admiral David G. Farragut's squadron was prevented from passing Port Hudson. In the fighting, USS Mississippi (10 guns) was lost. 

Armies & Commanders

Union

  • Major General Nathaniel Banks
  • 30,000 to 40,000 men

Confederate

  • Major General Franklin Gardner
  • around 7,500 men

Initial Moves

In approaching Port Hudson, Banks dispatched three divisions west with the goal of descending the Red River and cutting off the garrison from the north. To support this effort, two additional divisions would approach from the south and east. Landing at Bayou Sara on May 21, Augur advanced toward the junction of the Plains Store and Bayou Sara Roads. Encountering Confederate forces under Colonels Frank W. Powers and William R. Miles, Augur and Union cavalry led by Brigadier General Benjamin Grierson engaged. In the resulting Battle of Plains Store, Union troops succeeded in driving the enemy back to Port Hudson.

Banks Attacks

Landing on May 22, Banks and other elements from his command quickly advanced against Port Hudson and effectively had surrounded the town by that evening. Opposing Banks' Army of the Gulf were around 7,500 men led by Major General Franklin Gardner. These were deployed in the extensive set of fortifications that ran for four and half miles around Port Hudson. On the night of May 26, Banks held a council of war to discuss an attack for the following day. Moving forward the next day, Union forces advanced over difficult terrain towards the Confederate lines.

Beginning around dawn, Union guns opened on Gardner's lines with additional fire coming from US Navy warships in the river. Through the day, Banks' men conducted a series of uncoordinated assaults against the Confederate perimeter.

These failed and his command sustained heavy losses. The fighting on May 27 saw the first combat for several African-American regiments in Banks' army. Among those killed was Captain Andre Cailloux, a freed slave, who was serving with the 1st Louisiana Native Guards. Fighting continued until nightfall when efforts were made to retrieve the wounded.

A Second Attempt

The Confederate guns briefly opened fire the next morning until Banks raised a flag of truce and asked permission to remove his wounded from the field. This was granted and fighting resumed around 7:00 PM. Convinced that Port Hudson could only be taken by siege, Banks began constructing works around the Confederate lines. Digging through the first two weeks of June, his men slowly pushed their lines closer to the enemy tightening the ring around the city. Emplacing heavy guns, Union forces began a systematic bombardment of Gardner's position.

Seeking to end the siege, Banks began planning for another assault. On June 13, the Union guns opened with a heavy bombardment which was supported by Farragut's ships in the river. The next day, after Gardner refused a demand to surrender, Banks ordered his men forward. The Union plan called for troops under Grover to attack on the right, while Brigadier General William Dwight assaulted on the left. In both cases, the Union advance was repulsed with heavy losses. Two days later, Banks called for volunteers for a third assault, but was unable to obtain sufficient numbers.

The Siege Continues

After June 16, fighting around Port Hudson quieted as both sides worked to improve their lines and informal truces occurred between the opposing enlisted men.

As time passed, Gardner's supply situation became increasingly desperate. Union forces continued to slowly move their lines forward and sharpshooters fired on the unwary. In an effort to break the deadlock, Dwight's engineering officer, Captain Joseph Bailey, oversaw the construction of a mine under a hill known as the Citadel. Another was begun on Grover's front extending under Priest Cap.

The latter mine was completed on July 7 and it was filled with 1,200 pounds of black powder. With construction of the mines finished, it was Banks' intention to detonate them on July 9. With the Confederate lines in a shambles, his men were to make another assault. This proved unnecessary as news reached his headquarters on July 7 that Vicksburg had surrendered three days earlier. With this change in the strategic situation, as well as with his supplies nearly exhausted and no hope of relief, Gardner dispatched a delegation to discuss Port Hudson's surrender the next day. An agreement was reached that afternoon and the garrison formally surrendered on July 9.

Aftermath

During the Siege of Port Hudson, Banks' suffered around 5,000 killed and wounded while Gardner's command incurred 7,208 (approx. 6,500 captured). The victory at Port Hudson opened the entire length of the Mississippi River to Union traffic and severed the western states of the Confederacy. With the capture of the Mississippi complete, Grant turned his focus east later that year to deal with the fallout from the defeat at Chickamauga.

Arriving at Chattanooga, he succeeded in driving off Confederate forces that November at the Battle of Chattanooga.