Maj. Gen. Theophilus H. Holmes planned an attack on the Mississippi River port city of Helena, situated 70 miles downriver from Memphis and 230 miles above Vicksburg. Since its occupation in July 1862 by Union troops, under Maj. Gen. Samuel Curtis, Helena had been a constant thorn in the side of Arkansas Confederates. Not only did the occupation allow Union forces to control trade and to influence the sentiments of the surrounding region, but the Union garrison also posed a constant threat of invasion of the rest of Arkansas.
The Confederate high command thought that an attack on the Union base there might alleviate those problems and might draw some of Maj. Gen. Ulysses S. Grant's troops away from the Siege of Vicksburg. If Helena could be captured, it would provide the Confederates with a strategic position on the river to compensate for the possible loss of Vicksburg.
Maj. Gen. Sterling Price was eager to attack. He informed Holmes that his men were rested and in an excellent mood, and that he "entertained no doubt of... being able to crush the foe" at Helena. Holmes noted, "If [as reports indicated] there are 4,000-5,000 men in Helena, fortified as they are, to take it would cost too much."
Maj. Gen. Benjamin Prentiss and his command had been hearing rumors of an impending attack on Helena. They got information from Union scouts and local sympathizers. Prentiss acted on this information he recieved and began to build up his fortifications around town. He ordered rifle-pits to be dug and substantial breastworks to be thrown up. The town's principal defense was Fort Curtis, an earthen bastion on the western edge of town. To supplement this position, Prentiss placed 4 artillery batteries, protected by breastworks and rifle pits, on 4 hills that formed a rough semicircle around the town. He designated these batteries, north to south, as A, B, C, and D. Additional firepower was provided by the Union steamer USS Tyler, which was anchored off the river bank. It was armed with one 30-pound Parrott gun and six 8-inch smoothbore cannon.
Helena was surrounded by a series of hills cut by deeply thicketed ravines. The fortifications were largely the work of Maj. Gen. Benjamin Mayberry Prentiss. He was given command of the District of Eastern Arkansas, which was headquartered at Helena. The departure of a large number of troops for Vicksburg left Prentiss with only 4,000 effectives. He began to use Helena's topography to strengthen his position.
The Confederate plan called for Price's infantry and Marmaduke's cavalry to move from Jacksonport to the vicinity of Helena, where they would unite with forces from Little Rock under the command of Brig. Gen. James Fagan. Holmes would travel from Little Rock, accompanied by Arkansas Governor Harris Flanagin, to take personal command of the attack .
For 10 days previous to the battle, indications of a premeditated attack on Helena began to multiply; citizens from the county were not permitted to come to the Union lines; disaffected residents were unusually reserved, and the enemy's pickets were pushed forward and strengthened.
Prentiss expected the coming Confederate attack, if one was to be made, would be sudden, and at an early hour in the morning. It was, therefore, ordered, a week previous to the battle, that the entire garrison should be up and under arms at 2:00 A.M. each morning.
On July 3, Holmes arrived at the Allen Polk house, 5 miles from Helena. His arrival did little to arouse the confidence of the troops. What Holmes found when he arrived probably caused him to wish he were somewhere else as well. Holmes planned a coordinated attack from 3 sides. Marmaduke's 1,750 dismounted cavalry would attack Rightor Hill northwest of town. He would be supported on his left by a cavalry brigade under Brig. Ben. L. M. Walker. Walker was charged with preventing any Union reinforcements from reaching Rightor Hill. Fagan's 1,339 men would move against Hindman Hill southwest of town. The main thrust would be made by Price's 3,095 men against Graveyard Hill near the center of the Union defensive perimeter. Holmes ordered all attacks to begin at daylight on July 4.
On July 4, Marmaduke's advance toward Rightor Hill was stalled by enfilading artillery and small-arms fire from Union troops along the levee to his left and rear. He expected Walker to protect his left flank, but Walker was concerned about his own left flank and refused to move to Marmaduke's aid.
Farther to the Confederate right, a problem of communication hindered the assault. Fagan had interpreted Holmes's order to attack "at daylight" to mean at first light, but when his men began their assault on Hindman Hill, they came under withering fire from Battery C on Graveyard Hill, which, to Fagan's consternation, was not under attack by Price. Unable to bring along Fagan's artillery because of the felled trees that obstructed the road and pounded by artillery from Batteries D and C, the Confederates moved up the hill "amid the leaden rain and iron hail." They managed to overrun the protecting rifle pits, but were pinned down just short of the battery. More than an hour after Fagan launched his attack, Price began his attack on Graveyard Hill.
Twice repulsed, the Confederates charged a third time. They carried the hill and captured the Union battery. Price immediately attempted to turn the captured cannon on the retreating Federals but found that the guns had been disabled. His had been the only element of the Confederate assault to reach its objective, and his troops continued to attract the fire of every available Union gun.
Holmes arrived on Graveyard Hill shortly after its capture and proceeded to give a series of confusing and contradictory orders that only made matters worse. Some of Price's men moved to attack Fort Curtis, while others attempted to go to the relief of Fagan. But exhaustion, confusion, the heat, and the intense Union fire combined to render both attempts futile. Fagan's men were forced to retreat back through the rifle pits they had taken at such great cost earlier in the day.
At 10:30 A.M., realizing that the situation was hopeless, Holmes ordered a general retreat. The Confederates withdrew toward the Polk house, their rear guard skirmishing to cover their retreat until around 2:00 P.M. The attack had failed and the battle was over.
Prentiss had performed a defensive masterpiece. His fortifications had helped hold off the numerically superior Confederates. The USS Tyler had proved particularly devastating to the Confederates. Its commander, Capt. James M. Prichett, reported that the gunboat had fired 413 rounds during the battle.
Helena continued as an important Union enclave in the Trans-Mississippi theater and served as a base for the expedition that captured Little Rock. For the Confederates, the battle had been a disaster because nothing had been gained, and desperately needed men had been lost.