Keith was forced by community pressures into enlisting for the Confederacy. Malinda's sentiments originally were pro-South, but out of loyalty to her husband, she planned to desert with him at the first opportunity. Somehow the circumstances never quite developed that would allow them to carry out their plan.
Keith and Malinda fought together in three battles garbed in Confederate gray until March 1862 when Malinda was wounded in the shoulder. Keith carried her to the surgeon's tent, and in the process of removing the bullet the surgeon discovered that "Sam" was a woman. Keith pleaded with the surgeon not to expose her, but the surgeon agreed only to give Keith a short time to work out his next course of action.
Distraught about the probability of being separated from Malinda, Keith deliberately rubbed poison oak all over himself. By the next morning, his skin was blistered and swollen and he had a high fever. Fearing that he had small pox, the physicial confined him to his tent under guard to avoid contagion. It was decided to give him an immediate medical discharge on April 20, 1862.
Malinda quickly informed the incredulous Colonel Zebulon Vance (later Governor of North Carolina and a U.S. Senator) that she was a woman. After a surgeon verified her claim, she was discharged on the same day.
The Confederate records for Mrs. S. M. Blalock, 26th, Company F, state, "This lady dressed in men's cloths, Volunteered [sic], received bounty and for two weeks did all the duties of a soldier before she was found out, but her husband being discharged, she disclosed the fact, returned the bounty, and was immediately discharged April 20, 1862."
Keith and Melinda slowly found their way home to the mountains of western North Carolina to recuperate. Under constant threat of recall to Confederate service, they became outlaws and embarked on a campaign as Federal partisans and guerrillas in the Blue Ridge and Great Smoky Mountains of Western North Carolina and East Tennessee. They guided Union sympathizers and escaped Union prisoners through the mountains to safety in the North. Toward the end of the war they served as scouts and raiders with the 10th Michigan Cavalry.