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Battle of Thompson's Hill (Port Gibson)
May 1, 1863
Web Author's Notes:
The following is a description of the Battle of Thompson's Hill, also known as the Battle of Port Gibson, found on

Battle of Port Gibson

Maj. Gen. Ulysses S. Grant launched his march on Vicksburg in the Spring of 1863, starting his army south, from Milliken's Bend, on the west side of the Mississippi River. He intended to cross the river at Grand Gulf, but the Union fleet was unable to silence the Confederate big guns there. Grant then marched farther south and crossed at Bruinsburg on April 30. Union forces came ashore, secured the landing area and, by late afternoon, began marching inland. Advancing on the Rodney Road towards Port Gibson, Grant's force ran into Rebel outposts after midnight and skirmished with them for around three hours. The Battle of Port Gibson began the following day with a Union onslaught that could not be checked, and convincing Grant that the way to Vicksburg was now open.

Breakout from Bruinsburg

The movement off the beach head was delayed when it was discovered that McClernand's troops had not been adequately provisioned. With the last minute change in plans McClernand had rushed his troops to Hard Times and logistics had been overlooked. Now on the Mississippi side of the river they needed provisions before they could move forward. A lengthy delay was caused while three days rations were ferried across the river and distributed. As soon as the rations had been issued another problem became evident. No wagons had been allowed across the river while troops were still being moved. Transportation of food and ammunition from the landing had not been considered. Of the two items Grant considered ammunition more important. He ordered that any and all animals be seized to haul the heavy burdens. Horses, mules, oxen, and even dogs were used to drag the ammunition forward in "a motley train" of wagons and carts. Thomas Durham, a soldier from Indiana, recalled that the collection of oddly teamed animals and vehicles amounted to "no such sight has ever been seen since old Noah entered the Ark". The over burdened infantry troops were no less resourceful and innovative. Already weighed down with haversacks full of sixty rounds of ammunition and rations the soldiers fixed bayonets and stabbed through meat rations that no one wanted to leave behind. The weapons were then set to right shoulder shift with the precious cargo stuck to the end.

The main Federal column finally set out at 1730. For some unknown reason, probably faulty maps and lack of knowledge about the surrounding area, the lead element, 21st Iowa, avoided the most direct route, the Bruinsburg Road, and headed south in the direction of the Bethel Church. Their objective was the small crossroads town of Port Gibson. Roads from the town led to Vicksburg, Grand Gulf, and Jackson as well as the all important bridges across the Bayou Pierre which served as the last significant terrain obstacle to the Confederate bastion at Grand Gulf. Possession of the town would give Grant a numbered of tactical alternatives that would prevent the Confederate response from consolidating against any one attack. In the vanguard of the column Colonel Merrill place a 16 man patrol led by LTC Cornelius Dunlap. Their orders were to advance "until fired on by the enemy". Shortly after midnight they neared the Shaifer residence.

The Union troops were not the only ones marching. Left to his own devises for this long Bowen was finally getting some attention paid to his rapid fire stream of messages warning of the impending Union movement. Reacting to the sound of guns at Grand Gulf, Stevenson released the brigades of BG Edward Tracy and BG William Baldwin to move to Bowen's assistance from Vicksburg. While he waited the arrival of the much needed reinforcements Bowen proceeded to make dispositions with the troops he had available. Lacking cavalry (Adams was still off chasing Grierson), Bowen sent about 400 men from BG Martin Green's Arkansas Brigade to patrol the roads and establish an initial position near Port Gibson. The vanguard was comprised of the 21st Arkansas (-), 15th Arkansas and 12th Arkansas Sharpshooters under the command of Colonel J. E. Cravens. Bowen had to be careful not to strip away too much of his force. If the Bruinsburg landings proved to be a feint then Grant could use his gunboat access to Bayou Pierre to land a force to attack Grand Gulf directly. Accordingly he left Cockrell's Missouri Brigade there as protection and to serve as a reserve until the situation was developed.

BG Green arrived with the attached 6th Mississippi and additional artillery on the 30th and true to his aggressive nature began pushing his men forward. They established a defensive line across the Rodney Road near the Union Church. Tracy's much fatigued brigade arrived at 2200 and set up a similar position on the Bruinsburg Road on Green's right. In between the two positions was a nearly impassable terrain formed by ravines and heavy scrub vegetation. Green also dispatched Lieutenant William Tisdale and four soldiers of Company B, 12th Arkansas Sharpshooters to act as an early warning system. The small group established an outpost in the vicinity of the Shaifer House. The stage was set for the first large scale engagement of the 55 days. Approximately 6000 Confederates stood in the path of 22,000 Union soldiers.

Port Gibson -- Rodney Road

After midnight BG Green rode out personally to check on his outpost at Shaifer House and consult with LT Tisdale. As he tried to calm the nervous residents there a fusillade of bullets struck the wagon that they were preparing for their ride out of harm's way. LTC Dunlap's patrol had arrived and both the civilians and BG Green beat a hasty retreat; Mrs. Shaifer to safety and the general to warn his main line of troops.

The Union advance hastily overcame LT Tisdale's small band but were treated to a rude surprise when they neared the main Confederate position. A volley was delivered at 50 yards by soldiers of the 12th Arkansas Sharpshooters who were hidden behind a fence. The surprise encounter in the dark caused the Union Brigade commander, Colonel William Stone, to deploy not only the remainder of the 21st Iowa but the rest of the brigade as well. Two batteries of artillery were brought up, 1st Iowa and 1st Indiana, and the next three hours were spent in a gun duel and skirmishing. Darkness however prevented full scale operations. Stone, unwilling to risk night operations and the chance of running into a Confederate trap decided to wait until sunrise before making any bold move.

At the river darkness was also playing havoc with Grant's plan. Despite fires to illuminate the way and other precautions Horizon collided with Moderator while shuttling arms and supplies to the eastern side. Horizon went to the bottom with all the horses and equipment of an Illinois artillery battery. Grant was forced to cancel the shuttle until daylight or risk the loss of the valuable boats.

In preparation for the renewal of hostilities McClernand ordered BG Asa Carr to fully deploy his division against Green's position. In accordance with these orders Stone's brigade was joined by BG William Benton's brigade. BG Peter Osterhaus was sent to deploy his division against Tracy on the Bruinsburg Road.

At 0630 Carr started Benton's brigade forward in an effort to push Green off the ridge near the church. The Confederate skirmishers were pushed back on to the main line. The defense there quickly ran into trouble against the staggering odds. At about 0700 the supporting artillery reported that they were out of ammunition. Green sent a courier to Tracy asking for one regiment of troops and a section of guns. Tracy, not yet under full attack, reluctantly agreed and sent the 23rd Alabama and a section of Johnston's (Anderson's Battery) 12 pounders to assist. The reinforcements arrived about 0830 "under a heavy fire, and took position and fought bravely." Green's line was also buttressed by two resupplied guns of the Hudson Battery, under LT John Sweaney, that had withdrawn earlier. Despite a heroic effort the position could not be held and Johnston's guns were reversed.

Bowen understood the importance of the ridge to his position and led a counter attack by the 6th Mississippi and 23rd Alabama to retake the position. The effort was bloodily repulsed by Union artillery firing double canister. The unequal contest could not be maintained so Green ordered a withdrawal to avoid disaster. At 1100 the Confederates made their way back along the road in orderly fashion. About a mile and a half up the road they ran into Baldwin's brigade as they were making their way to the sound of the guns. Baldwin's men established a line across the Rodney Road about two miles southwest of Port Gibson while Green reorganized his troops. The 17th Louisiana and the 4th Mississippi were quickly engaged by the pursuing Federals. "The fire was kept up with but little intermission along our front until between 3 and 4 p.m." Cockrell arrived with two of his Missouri regiments, 3rd and 5th, and were sent to the far left to match the expanding Federal front. To break the stalemate Bowen ordered Baldwin and Cockrell to advance against the Union troops in their front to try their strength.

The 46th Mississippi was brought on line from a reserve position and preparations were made for the attack. Heavy fire of grape and canister prevented all but the 4th Mississippi from stepping off on the assault. The unfortunate 4th moved right into the guns of two waiting infantry brigades. Cockrell's men fared no better. His movement had been discovered and carnage awaited his attack, after an hour of brutal fighting Cockrell retreated with staggering losses (13k, 97w, 96m). The Confederates were forced to retreat to their start position where they faced an immediate Union counter attack. The Confederate batteries checked the Union advance but "in doing so killed and wounded several of our own men." The situation stabilized until 2100 when withdraw across the Bayou Pierre was ordered. After his command had crossed the bridge was burned and Baldwin reported to Bowen near the two primary bridges across the bayou.

Port Gibson -- Bruinsburg Road

BG Edward Tracy's position on the intersection of the Shaifer Road and Bruinsburg Road held double importance. Not only was it essential to the effort to delay the Union juggernaut but should it fall then Green's forces would be cut off from their escape route over the Bayou Pierre. Tracy's men relieved a company from Green's command on the night of the 30th and established a position on a ridge about a mile north of the Shaifer House. The exhausted men dropped to sleep almost immediately after assuming their positions. They were awakened by artillery fire at the Shaifer House to discover that they were oriented in the wrong direction. Originally emplaced to protect against an advance from the west they now realized that the primary threat lay to the south. Tracy altered his position by executing a change of front in the darkness.

At 0530 their new position was identified by McClernand. He became concerned that Tracy's Confederates posed a threat to the rear of Carr's division as it moved against Green. He immediately dispatched four companies of the 33rd Illinois to keep an eye on the threat while he scrambled to counter the threat. Tracy also saw the opportunity and began to deploy his forces for an advance. He filled the gap created by the departure of the 23rd Alabama (sent to reinforce Green) with the 30th Alabama while skirmishers from the 30th Alabama moved south along the Shaifer Road. After about a quarter mile advance the Confederate vanguard ran into the 33rd Illinois skirmishers moving in the opposite direction to establish a picket line. Like the fight on the Rodney Road the collision of these two small parties escalated very quickly.

BG Peter Osterhaus was ordered to develop the fight with the lead elements of his division as they came on line. The 7th Michigan Artillery prepped the field with a forty-five minute barrage before the 7th Kentucky and 49th Indiana started up the road. Tracy also got much needed help when the 46th Alabama and another section of guns arrived at 0800 after a long march from Vicksburg. Nevertheless the 31st Alabama skirmishers were pushed back on to the main line.

At 0845 Osterhaus sent the 42nd Ohio, 16th Ohio, and 22nd Kentucky on an assault into the center of the Confederate line. Using the ravine rutted terrain as a natural fortress Tracy's men mowed down the Union attackers. Osterhaus determined "it would have demanded too great a sacrifice of life to have persisted in the attack." The Federal attack inflicted a serious loss on the Confederates however. BG Tracy was dead at one of his batteries and command fell to Colonel Isham Garrott, 20th Alabama. Garrott admitted in his official report that he knew nothing of the plan of battle and dispatched a courier to Bowen for instructions. At 1100 the messenger returned with little guidance other than the position was to be held at all hazards.

Osterhaus, meanwhile, had decided that the best chance of defeating the Confederate defense was to hold the main line while a flanking movement was made by follow on troops. His recommendation was sent to the rear and adopted by Grant who detailed McPherson's Corps to conduct the flanking maneuver. McPherson's gave the mission to his lead division, under the command of MG John Logan. Logan's men took three hours deploying for the movement.

Garrott did not waste the time the Federal deployment granted him. He sent an urgent request to Bowen for reinforcements and ammunition. Bowen had little to offer him but Green's battered command that had reorganized behind Baldwin's line plus the newly arrived 6th Missouri from Cockrell's brigade to help Garrott hold the line against the rapidly growing Union strength. Green led the reinforcements "as speedily as the wearied condition of my men would admit." Upon arrival Green, without consulting Garrott, fell in on the left side of the contracted Confederate line instead of the badly used up right. According to Osterhaus, whose report did not appear in the original OR's, McPherson's men ignored the flanking maneuver and attempted a frontal assault of their own and were bloodily repulsed. At 1600 McPherson's troops finally moved around the Confederate right giving Osterhaus an opportunity to attack the weakened center. Colonel Eugene Erwin of the 6th Missouri, sensing the impending disaster ordered his men to fix bayonets and charge the Union line in a desperate spoiling attack. After a ninety minute struggle against overwhelming odds the 6th Missouri was forced to retreat. The time bought by this gallant action allowed Garrott to begin the withdrawal of the remainder of the Confederate force across Bayou Pierre. Erwin's action saved many of Tracy's (Garrott's) brigade but cost him 82 casualties out of 400 men. The fight at Port Gibson was over. The Confederate actions at Port Gibson represented a brilliantly led delaying action. Bowen's superb leadership, the excellent execution by his subordinate commanders, and stubborn battle waged by the severely outnumbered Confederate troops was wasted however. No significant action was taken by Pemberton to reinforce the effort and defeat the Union force before they could consolidate. Grant was loose in the interior of Mississippi.

Port Gibson: Aftermath (May 1-2, 1863)

As night closed in on the Port Gibson battlefields the situation calmed. The Confederate forces made an unmolested retreat across the Bayou Pierre as the exhausted Federal troops paused. The horrible work of recovering the dead and wounded was begun. A curious Fred Grant, the general's son, decided to lend a hand. A brief look at the mutilated corpses was enough to scare the young man away from that detail. Instead he moved on to assist with the wounded at a field hospital that was being established at a log house nearby. He found the situation there equally disturbing. He later wrote of the experience;

The scenes there were so terrible that I became faint and ill and making my way to a tree, sat down, the most woe-be gone twelve year old lad in America.

The day long fight had been costly for both sides. Union losses totaled 975 (131 killed, 719 wounded, 25 missing) while the partial returns from the Confederate forces set the toll at 832 (68 killed, 380 wounded, 384 missing). Despite the heavy losses Grant was determined to take up the fight on the morning of the 2nd.

At dawn the Union troops moved forward to find that the stubborn Confederates had left the field. Bowen had moved his troops first across the Little Bayou Pierre and then Big Bayou Pierre, burning the bridges behind them. At 0900 they finally made camp. The exhausted men fell on their arms. There was no hiding Grant's whereabouts or intentions now. The light finally came on in Pemberton's brain. He wired Jefferson Davis that Grant's seizure of a foothold in Mississippi had "completely changed (the) character of defense." He told Davis that;

Large reinforcements should be sent to me from other departments.

He feared that Jackson was threatened and a successful march on the capital would isolate Vicksburg. He did not, however, take advantage of the time gained by Bowen's valiant action. He did not significantly reinforce Bowen.

When he realized that he would receive only minimal assistance from Pemberton, Bowen abandoned the idea of defending the crossings of Bayou Pierre. He moved north of the Big Black. Not only was a strong position at a natural obstacle and choke point given up without a fight but he also ordered Grand Gulf evacuated as well. With the Bayou undefended defense of the fortress was made untenable by Grant's gains at Port Gibson. The magazines were destroyed but nine of the large guns were left in place. Without firing a shot Grant gained a river position that was adequate as a supply point for upcoming operations. Grant also called forward his most trusted subordinate. General Sherman brought his XVth Corps across the river on the 7th while engineers bridged the Bayou Pierre. Having successfully grasped the initiative from the Confederates Grant now had to decide the next move.

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