Unlike most Texas Unionists who simply put aside their feelings for the good of the state and supprt the Confederacy, former State Senator Martin Hart decided to act on his; he joined the Union Army. A resident of Greenville, Hart was a prominent lawyer, politician, land owner, and committed Unionist. To add fuel to his inner flame, his father, John F. Hart, was shot during a land dispute with wealthy slaveholders. The death of his father and the loss in court of the disputed land left Martin deeply embittered. Along with twenty-four others, he signed the “Address to the People of the State;” a circular that condemned slavery and foretold of its eventual destruction. The “Texas Republican,” a Marshall, Texas newspaper, denounced the document as “an insidious attempt to prejudice the nonslaveholder, not only against slaveholders, but slavery itself.”
In August, 1862, Hart and thirty-seven followers, known locally as the Greenville Guards, left North Texas for Ft. Smith, Arkansas. Upon reaching his destination, he obtained a commission to raise a Confederate company. The commission was only part of an elaborate ruse; Hart used the commission to pass through Confederate lines into Union held Southwest Missouri. In Springfield, he obtained a captain’s commission to raise a company for the Union Army. Hart hoped to use his new command to recruit fellow North Texans for an entire regiment, the 1st Texas Cavalry Regiment. Part of his command was sent back to North Texas to help recruit in Hunt County for his new regiment. Meanwhile, the newly commissioned Captain Hart and his remaining men began operations in Northwest Arkansas. With personal scores to settle, ragtag, ill-disciplined Arkansas Unionists began to sign on with Hart's growing company.
Union General Francis Jay Herron ordered Hart to pursue the notorious Confederate guerilla, James Ingraham. The elusive Ingraham managed to avoid Hart while ambushing Union wagon trains in Benton County. Ingraham himself would become a target after the war; the son of one of his victims would gun him down. In addition to hunting Ingraham, Hart conducted operations against regular Confederate forces. In January, 1863, he attacked the rear guard of Colonel Joseph W. Speight’s 15th Texas Infantry Brigade, capturing and paroling 20 soldiers. According to an Arkansas local, Sophia Kannady, Hart was a perfect gentleman. "Hart lifted me off my horse. He was a fine looking man, and while he robbed us of our team, provisions and everything else, he did not cause me to be searched nor did he take my horse." The gentle niceties would soon end.
Word of Hart’s turncoat activities trickled down to North Texas, causing a widespread panic that he was going to invade his home state. Confederate General William Steele alerted his superiors that Hart was wreaking havoc in the countryside with a bloodthirsty band of Unionists and deserters. Lieutenant Colonel R. P. Crump of the 1st Texas Partisan Rangers began a determined pursuit of Hart.
As with most guerilla warfare units, the fine line between military activity and criminal activity can become blurred during the course of war. Military objectives become lost in the shuffle as personal scores are settled. Nowhere was this more true than in the Southwest Missouri and Northwest Arkansas; Bushwhackers, Jayhawkers and Red Legs showed little mercy toward their victims. Hart’s Arkansas Unionists, with a deep rooted hatred of slaveholders, took their hostilities out on their neighbors. In Charleston, two prominent planters, Edward Richardson and DeRosey Carroll, were beaten then shot repeatedly after being called out of their homes.
Despite being held up by the harsh winter weather, a detachment of Crump’s men encountered a local Arkansas Unionist who mistook them for Union cavalry, probably because of their captured Union apparel. Utilizing their mistaken identity, Crump’s men persuaded the Unionist to lead them to Hart’s camp. At 2:00 AM, January 19, 1863, Crump surrounded Hart’s camp near Ft. Smith on the Poteau River. Hart and his Greenville Guards were holed up inside a blacksmith shop. Crump shouted, "Unconditional surrender within five minutes, or I shall fill the shop full of holes!" Hart and twenty three of his men surrendered. He was taken to Ft. Smith for a drumhead court-martial. Both Confederate and Union authorities in the region usually didn't offer clemency toward guerillas. Hart was hanged from a tree branch and buried in an unmarked grave. After the war, his body was exhumed and reburied at the National Cemetery at Ft. Smith.