# Battle of Wilson's Creek

The Battle of Wilson's Creek, also known as the Battle of Oak Hills, was the first major battle of the Trans-Mississippi Theater of the American Civil War. It was fought on August 10, 1861, near Springfield, Missouri.
In August, Confederates under Brigadier General Benjamin McCulloch and Missouri State Guard troops under Maj. Gen. Sterling Price approached Brig. Gen. Nathaniel Lyon's Army of the West, camped at Springfield. On August 10, Lyon, in two columns commanded by himself and Col. Franz Sigel, attacked the Confederates on Wilson Creek about 10 miles (16 km) southwest of Springfield. Confederate cavalry received the first blow and retreated from the high ground. Confederate infantry attacked the Union forces three times during the day but failed to break through. Eventually, Sigel's column was driven back to Springfield, allowing the Confederates to consolidate their forces against Lyon's main column. When Lyon was killed and General Thomas William Sweeny wounded, Major Samuel D. Sturgis assumed command of the Union forces. When Sturgis realized that his men were exhausted and lacking ammunition, he ordered a retreat to Springfield. The battle was reckoned as a Confederate victory, but the Confederates were too disorganized and ill-equipped to pursue the retreating Union forces.
Although the state remained in the Union for the remainder of the war, the battle effectively gave the Confederates control of southwestern Missouri. The victory at Wilson's Creek also allowed Price to lead the Missouri State Guard north in a campaign culminating at the siege of Lexington, Missouri.

## Background
### Military and political situation

At the beginning of the American Civil War in 1861, the state of Missouri was a politically divided border state. Permitting slavery, the state had long-standing cultural and economic ties to the Southern United States, although these had declined in the years leading up to the outbreak of war. While the state's newly-elected Governor Claiborne Fox Jackson did not openly support seceding from the United States and joining the Confederate States of America, he harbored pro-Confederate sympathies. The outgoing governor had appealed to the state to maintain "armed neutrality" during the conflict. On April 20, a secessionist mob seized the arsenal in Liberty, Missouri, increasing Union concerns in the state. Unionist activities in the state increased as well.
Under an 1858 state law governing the militia, Jackson called out the Missouri Volunteer Militia (MVM) for mustering and training. Those companies from the St. Louis area encamped at Lindell's Grove, creating a camp they named Camp Jackson. These militia numbered close to 900 men under the command of Brigadier General Daniel M. Frost and were mostly pro-secession and pro-Confederate. Jackson had secretly obtained two cannons from the Confederate government, and Jackson and Frost intended to use the milita to capture the St. Louis Arsenal. Capt. Nathaniel Lyon of the United States Army was aware of these developments and was concerned the militia would move on the arsenal. Thomas W. Sweeny was put in command of the arsenal's defense, and Lyon surrounded the militia camp with Union troops and home guards on May 10, forcing the surrender of the militia in what became known as the Camp Jackson affair. When he marched the prisoners through the streets to the arsenal, some angry members of the crowd began to press against the procession. Taunts and jostling eventually led to gunfire and many deaths. Most of the dead were civilians, but several soldiers and members of the militia were also killed.
A day later, the Missouri General Assembly created the Missouri State Guard (replacing the MVM) theoretically to defend the state from attacks by perceived enemies on either side of the war. The governor appointed Sterling Price as the commander with the rank of major general of state forces. The state guard was divided into divisions, with each division consisting of units raised from a military district of Missouri and commanded by a brigadier general. Because many of the organization's recruiting areas were behind Union lines, many divisions were the size of a brigade, consisting of only a few regiments. Seeing Missouri's tilt to the South, William S. Harney, the Federal commander of the U.S. Army's Department of the West (which included Missouri) negotiated the Price-Harney Truce on May 21, which nominally created cooperation between the U.S. Army and the MSG to maintain order in Missouri. Under the agreement, the Missouri government would keep peace in the state; so long as the situation remained peaceful, Harney would not intervene with the military. If intervention was necessary, Harney agreed to cooperate with the state forces in peace-keeping. Effectively, this required the federal government to be neutral in the conflict.
After complaints by Missouri Unionists, Harney was replaced by Lyon (who was promoted to brigadier general of volunteers), further undermining the fragile truce. On June 12, Lyon and Jackson met at the St. Louis' Planter's House Hotel in a last attempt to avoid a resumption of fighting. Both sides were inflexible, with Lyon demanding the right to inspect any area of the state for Confederate intervention, and Jackson refusing and demanding that Federal forces be restricted to the St. Louis metropolitan area. Colonel Snead, the only surviving witness to that meeting, stated that the meeting ended with Lyon reportedly saying:
   ...rather than concede to the State of Missouri for one single instant the right to dictate to my government in any matter however unimportant, I would see you, and you, and you, and you, and every man, woman, and child in the State, dead and buried. This means war.
Lyon sent a force under Sweeney to Springfield while his own forces quickly captured the capital and pursued Jackson, Price, and the now-exiled state government across Missouri. Skirmishes followed, including the Battle of Boonville on June 17 and the Battle of Carthage on July 5. In light of the crisis, the delegates of the Missouri Constitutional Convention that had rejected secession in February reconvened. On July 27, the convention declared the governor's office vacant and selected Hamilton Rowan Gamble to be the new provisional governor.
After the defeat at Carthage, Sigel withdrew to Springfield. On July 7, Lyon and the forces with him were joined at Clinton, Missouri, by a force that had arrived from Kansas commanded by Major Samuel D. Sturgis. These troops with Lyon reached the Springfield area on July 13, although Lyon did not immediately allow his troops to enter Springfield until they had been resupplied, as a precaution against looting. By the end of July, the Missouri State Guard was camped about 75 mi (121 km) southwest of Springfield and had been reinforced by Confederate Brigadier General Benjamin McCulloch and Arkansas state militia Brigadier General N. Bart Pearce. Price and McCulloch developed plans to attack Springfield, but Lyon marched out of the city on August 1 in an attempt to surprise the Southern forces. The armies' vanguards skirmished at Dug Springs, Missouri on August 2. The Union force emerged as the victor, but Lyon learned he was outnumbered by more than two-to-one and retreated back to Springfield. McCulloch, now in command of the Missourian army, gave chase. By August 6, his force was encamped at Wilson Creek, 10 miles (16 km) southwest of the city. Price favored an immediate attack on Springfield but McCulloch, doubtful about the quality of the Missouri State Guard, preferred to remain in place. After Price threatened to launch an attack without his support, McCulloch agreed to an attack at dawn on the 10th but when a rainstorm started during the evening of the ninth, he canceled his plans and ordered his troops back to camp.
Outnumbered, with many of his men's enlistments expiring or about to expire, and aware that he would not be receiving assistance from St. Louis, Lyon's only logical option was to withdraw to Rolla, Missouri. However, the naturally aggressive Lyon did not want to withdraw without a fight; it was hoped that such a fight would delay or discourage pursuit. The decision to attack was made on August 8, with the offensive movement to begin late the next day. At a council of war on the afternoon of August 9, Sigel proposed striking McCulloch in a pincer movement, which would split the already outnumbered Union force; he planned to lead 1,200 men in a flanking maneuver while the main body under Lyon struck from the north. Lyon had previously rejected an earlier plan from Sigel involving an attack by divided forces. While other officers opposed the decision, Lyon concurred with Sigel's plan, which was adopted. The Union army marched out to battle late on August 9; it was rainy for part of the march. Part of Lyon's command was left in Springfield, tasked with guarding the city and preparing for an evacuation in case of defeat.

## Opposing forces

* Key Union commanders
* Brig. Gen. Nathaniel Lyon, USA
* Col. Franz Sigel, USA
* Maj. Samuel D. Sturgis, USA
* Key Confederate commanders
* Maj. Gen. Sterling Price, MSG
* Brig. Gen. Ben McCulloch, CSA
* Brig. Gen. Nicholas Bartlett Pearce, CSA

### Union

Lyon's army was known as the Army of the West. This army was formed from three bodies of troops: one that had accompanied Lyon south from Boonville; troops that had moved from Fort Leavenworth, Kansas, under the command of Sturgis; and a force that had moved down from St. Louis commanded by Sweeny. Sweeny's troops had left St. Louis before he did, and these soldiers were commanded by Sigel earlier in the campaign. In late July, Lyon organized his command into four brigades, commanded by Sturgis, Sigel, George L. Andrews, and George W. Dietzler. Many of Lyon's soldiers earlier in the campaign had enlistment terms of only ninety days, and in July roughly 2,000 soldiers left Lyon's army to be discharged in St. Louis. At the battle, Lyon's force numbered 5,431 men. Further troops remained behind in Springfield, including a 1,200-man Home Guard unit.

### Confederate

McCulloch's army was known as the lacked a formal name, although he referred to it as the Western Army. Pearce referred to it as the Army of Arkansas or the Consolidated Army. Price did not consider the Missouri State Guard to be party of the Confederacy, and in June Jackson had delivered a speech arguing that the Missourians were bound to the United States Constitution, but that loyalty to Missouri bore precedence and that the United States government itself was behaving in an unconstitutional manner. While Pearce's troops were clearly subordinate to McCulloch, the same could not be said about Price's MSG. Price eventually offered overall command to McCulloch, who accepted the responsibility. Many of the soldiers were armed only with civilian weapons, and roughly 2,000 unarmed MSG soldiers accompanied the march. The presence of both these unarmed men and a number of Missouri camp followers breached an earlier agreement reached between Price and McCulloch. Including the unarmed Missouri militia, the Western Army numbered an estimated 12,125 men at Wilson's Creek. McCulloch viewed the MSG as undisciplined and unreliable.

## Battle

At first light on the morning of August 10, the Union began a surprise attack on the opposing forces. Lyon's force overran the enemy camps and took the high ground at the crest of a ridge, which would become known as "Bloody Hill". Early Union hopes for a rout were dashed, however, when the artillery of the Pulaski Arkansas Battery unlimbered and checked the advance, which gave Price's infantry time and cover to organize lines on the south slope of the hill. Lyon organized a line on the southern slope of Bloody Hill, from which he launched an unsuccessful counterattack. Price launched a series of frontal and flank attacks but was also unsuccessful; a shortage of ammunition in the Confederate army was a factor in the Confederate defeats.
The two Union forces lost contact with each other, with no means of communicating or supporting each other if anything went wrong. Sigel's attack was successful at first; the brigade arrived in the Confederate rear soon after dawn. Artillery fire routed the Confederate cavalry units, which were encamped at Sharp's farm. Sigel began a pursuit, but stopped along Skegg's Branch. During the break, he failed to post skirmishers, leaving his left flank open for an attack. Meanwhile, McCulloch rallied several Confederate units, including the 3rd Louisiana Infantry and the 3rd Division from the Missouri State Guard, to lead a counterattack. Sigel's men mistook the 3rd Louisiana for the 1st Iowa Infantry (which also wore gray uniforms) and withheld their fire until the Confederates were nearly upon them. His flank was consequently devastated by the counterattack, and his brigade was routed, losing four cannons. Sigel and his men fled the field, leaving the force under Lyon, Sweeny, and Sturgis holding out alone.
With the rout of Sigel's flank, the momentum of the battle shifted in the South's favor. Lyon was wounded twice, and worried that "the day was lost", he attempted to lead a counterattack. However, Lyon was shot in the heart, and the charge fell apart after his death. Lyon became the first Union general to be killed in the war. General Sweeny was shot in the leg, and Major Sturgis, as the highest ranking Regular Army officer, assumed command of the Union army. Despite still being in a defensible position atop the hill, Union supplies were low and morale was worsening. By 11:00 a.m., the Union forces had already repulsed three separate Confederate charges. Ammunition and men were nearly exhausted, and Sturgis retreated rather than risk a fourth Confederate attack.

## Aftermath

The casualties were about equal on both sides – around 1,317 Union and an estimated 1,232 Confederate/Missourian/Arkansan soldiers were either killed, wounded, or captured. Though the Confederate force won the field, they were unable to pursue the retreating Union forces to Rolla. Price wanted to start a pursuit of the Union force immediately, but McCulloch refused, worried about the quality of the Missouri State Guard and the length of his supply line back to Arkansas. With the victory, Price's Missouri Guard began an invasion of northern Missouri that culminated in the First Battle of Lexington on September 20. The Confederate and Arkansas forces withdrew from the state.
After falling back to Springfield, Sturgis handed command of the Union army over to Sigel. At a council of war that evening, it was agreed that the army had to fall back to Rolla, beginning at 3 a.m. the next morning. However, Sigel failed to get his brigade ready at that time, forcing a delay of several hours. Along the retreat route, Sigel's men took several lengthy delays to prepare meals; this caused the other officers to force Sigel to turn command back over to Sturgis.
On October 30, the Missourians under Price and Jackson formally joined the Confederate cause in Neosho, Missouri. A rump of the Missouri State Assembly meeting in Neosho passed the resolutions for Missouri secession and Jackson became (nominally) the Governor of Confederate Missouri (Jackson had never accepted his July removal from office by the State Convention). However, the secession action was never accepted by most of the population of Missouri, and the state remained in the Union throughout the war. What little control Price and Jackson did have was diminished by Confederate reverses during the Battles of Fredericktown on October 21 and the First Battle of Springfield on October 25. The Confederate state government was soon forced to leave the state.
By early 1862, Price withdrew from southwestern Missouri in the face of an advance led by Union Major General Samuel Ryan Curtis. Confederate Major General Earl Van Dorn took command of Price's and McCulloch's combined forces, but was defeated by Curtis at the Battle of Pea Ridge in Arkansas, in a multi-day battle that concluded on March 8. Jackson died in December 1862. After Curtis's victory, the state remained firmly in Union hands, but was wracked by devastating guerrilla warfare afterwards. In 1864, Price led an expedition to reclaim Missouri for the Confederacy, but this ended in a disastrous Confederate defeat. This was the last major campaign in the war west of the Mississippi River. The war ended in 1865 with a Confederate defeat. In the 1890s, five Union soldiers who had fought in the battle were awarded the Medal of Honor for their actions at Wilson's Creek: Lorenzo Immell, John Schofield, Henry Clay Wood, William M. Wherry, and Nicholas Bouquet.
The Battle of Wilson's Creek was the first major battle fought in the Trans-Mississippi theater of the war. The battle was known as the Battle of Oak Hills in the Confederacy, and is sometimes called the "Bull Run of the West".

## Battlefield preservation

The site of the battle has been protected as Wilson's Creek National Battlefield. The National Park Service operates a visitor center featuring exhibits, a fiber optic map displaying the course of the battle, and a research library. Living history programs depicting various aspects of the soldier's experience of that area are presented on weekends seasonally. With the exception of the vegetation and the addition of interpretive hiking trails and a self-guided auto tour route, the 1,750 acres (7.1 km$^2$) battlefield has changed little from its historic setting, allowing visitors to experience the battlefield in nearly pristine condition. The home of the Ray family, which served as a Confederate field hospital during the battle, has been preserved and represents one of only two structures in existence during the battle to still be extant on the park today (the other being a springhouse). In addition, the American Battlefield Trust has preserved 278 acres (1.13 km$^2$) of the Wilson's Creek battlefield.