After Texas secession in February 1861, he resigned his Senate seat and returned to Hunt County. In the summer of 1862 he received a Confederate commission with permission to raise a company and operate in northwest Arkansas. Using his commission to travel through Confederate lines, he and his followers marched to southwest Missouri, where they apparently received Union army papers. Hart returned to Arkansas, led a series of rear-guard actions against Confederate forces, and is alleged to have murdered at least two prominent secessionists. He and some of his followers were captured by Confederate troops on January 18, 1863, and taken to Fort Smith, where he and his first lieutenant, J. W. Hays of Illinois, were court-martialed and hanged, on January 23, 1863. DS, one page, 7.5 x 11.5, September 30, 1839. Handwritten power of attorney document for Hart appointing another gentleman to handle his affairs. In very good condition, with scattered soiling and toning, partial separations along horizontal folds lower portion of text a couple shades lighter due to decreased ink flow. R&R COA.
