 Complete the following phrase:  The 10th Regiment Missouri Infantry was an infantry regiment that served in the Confederate States Army during the American Civil War. The regiment was organized on November 10, 1862 and was assigned to the brigade of Brigadier General Mosby M. Parsons. The regiment fought at the Battle of Prairie Grove, where both the regiments colonel and lieutet colonel were killed. The regiment fought at the Battle of Helena on July 4, 1863, where it suffered heavy casualties. Beginning in late 1863, the 12th Missouri Infantry Regiment was attached to the regiment; the men of the 12th Missouri Infantry were officially merged into the regiment in late 1864. The regiment fought at the battles of Pleasant Hill and 