Frances Louisa Clayton, also known as Frances Clalin or Jack Williams, was an American woman who fought for the Union Army disguised as a man in the American Civil War. Before the Civil War broke out, Clayton and her husband lived in Minnesota. Once the fighting broke out, Clayton and her husband set off to Missouri to enlist in the Union Army, in hopes that enlisting in a different state would help disguise Frances Louisa Clayton’s identity. While her husband enlisted under his real name, Francis Clayton enlisted under the name Jack Williams. They both joined a Missouri regiment and fought along side each other for twenty-two months. It is said that Clayton fought in eighteen battles and served in both the cavalry and artillery units. Clayton is said to have been injured three times in battle, but her identity was never revealed. Clayton was described as a very tall and very masculine looking individual who would partake in male vices such as smoking, tobacco chewing, drinking, gambling, and swearing. While serving for the Union Army, Clayton became an accomplished horseman and a great swordsman. Clayton’s service came to an end at the Battle of Stones River, where her husband was killed on the front lines during a charge and reported that she had to walk over his body to continue the attack. Shortly after this day, Clayton reported her secret and was discharged from the army. Clayton’s story became known after her service when it was reported in many different newspapers. Her stories were widely circulated although several accounts contain contradictory information. Some reported that she was never discovered as a woman while others stated that she was discharged after being medically examined for a bullet to the hip. While attempting to return to Minnesota to collect her and her husband’s pay, her train was ambushed by Confederates. The last known reports described her heading to Washington, D.C. Several photographs of Frances Louisa are known to exist, with two of them taken in Boston. These two photographs show Clayton dressed in women’s clothing while the other depicts her in uniform. The only knowledge about Clayton, besides the photographs, came from her own words reported to newspapers.