Captain Cook Caught Out at Cole Camp (19 JUN 1861)

Photo By Erin Thompson | Map of Benton County from “Colton’s New Map of Missouri,” 1851 (Library of Congress)  

UNITED STATES

09.11.2026

Story by Erin Thompson 

U.S. Army Intelligence Center of Excellence

On June 19, 1861, Confederate Capt. Walter S. O’Kane led an element of the Missouri State Guard against a regiment of the Union Home Guard under Capt. Abel H.W. Cook near the town of Cole Camp. O’Kane’s victory depended on intelligence gathered from within the Union camp and Cook’s inexperience in command.

Despite being a slave state, most Missourians opposed the secession of the southern states from the Union in late 1860, so long as the federal government did not encroach on slaveholder rights or “employ force against the seceding states.” Thus, the Confederate assault on Fort Sumter in April 1861 and the subsequent buildup of a Union army caused considerable strife. In response, Governor Claiborne F. Jackson organized the Missouri State Guard to oppose any incursion into Missouri by federal forces.

In early May, Union Brig. Gen. Nathaniel Lyon captured a Confederate contingent at Camp Jackson outside St. Louis. The incident sparked deeper resentment between pro- and anti-secessionists across Missouri. As the Union secured St. Louis, Governor Jackson fled the capital at Jefferson City and ordered the State Guard to withdraw northwest, where he hoped to take control of the Missouri River for the Confederacy. Jackson was instead routed by Lyon at the Battle of Boonville on June 17. While Jackson’s forces fled south, Lyon remained at Boonville awaiting reinforcements before he could push the State Guard completely out of Missouri.

A week before the Boonville battle, Captain Cook had hastily assembled approximately 700 Union volunteers—predominately German immigrants—near the town of Cole Camp at a farm they called Camp Lyon. Confederate Captain O’Kane, 20 miles south in Warsaw, had assembled his own force and was concerned about Cook’s ability to delay Jackson’s retreat, as Cole Camp lay directly in the path of the fleeing State Guard. To neutralize the threat, O’Kane needed intelligence on Cook’s strength and disposition at Camp Lyon.

O’Kane turned to Benton County Sheriff Bartholomew W. Keown who, under the guise of serving an arrest warrant for Cook and his quartermaster on June 16, easily gained access to the camp. He learned Cook’s force was spread out across adjoining farms, lacked military experience, were poorly trained and disciplined, had insufficient firearms and munitions, and were alleged to enjoy alcohol to excess. To make matters worse, Cook allowed around 300 men to return home despite persistent rumors of an impending attack from Warsaw.

Pro-Unionist slaveowner John Tyree had also heard the rumors. While on business in Warsaw on June 18, he observed O’Kane’s 350 troops as they trained for the ambush. Tyree rushed to Camp Lyon and relayed what he had witnessed to Cook. The inexperienced and ill-prepared Cook informed his subordinate commanders, placed a few sentries around the camp, and ordered couriers to retrieve the soldiers he’d sent home, but otherwise did not assume a defensive position.

In the early morning of June 19, O’Kane set out for Cole Camp and soon encountered the returning Tyree, whom he interrogated and then executed as a spy. The Confederates then made their way towards Camp Lyon, quickly dispatching two of the sentries. The third fled to a nearby barn where a number of Cook’s men were sleeping. O’Kane’s men followed and overpowered the disoriented men in the barn. Other Union companies sleeping nearby were roused. While some attempted to form a defense, others were deceived by the U.S. flag being flown by O’Kane and did not engage until they were fired upon. Captain Cook was notably absent from the fight.

The result was thirty-five Union dead, sixty wounded, and twenty-five captured; the rest were in disorganized retreat. The Confederates suffered about seven killed and two dozen wounded, but they did acquire a sizeable collection of muskets. While O’Kane’s victory did not reclaim Missouri for the Confederacy, it allowed Jackson and the Missouri State Guard to move unimpeded further out of Lyon’s grasp.

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Article by Erin E. Thompson, USAICoE Staff Historian. New issues of This Week in MI History are published each week. To report story errors, ask questions, request previous articles, or be added to our distribution list, please contact: [e-mail].

• Date Taken: 09.11.2026
• Date Posted: 09.11.2026 14:10
• Story ID: 574443
• Location: US