From Guide to Missouri Confederate Units, 1861-1865 by James E. Mcghee, Page 184:
"The 1st & 4th Infantry followed the retreating Federal army to Nashville, but stayed there only briefly, for the 1st Missouri Brigade soon moved south to the Duck River to build fortifications. After the disastrous Tennessee Campaign, the brigade retreated to Mississippi and then moved to the defense of Mobile, Alabama. On April 9, 1865, a superior enemy force overwhelmed the garrison at Fort Blakely, including the 1st Missouri Brigade, and compelled its surrender after a short fight. The remnant of the 1st & 4th Regiment remained imprisoned at Ship Island, Mississippi until the war ended shortly thereafter. The few men left in the regiment received paroles at Jackson, Mississippi, on May 13, 1865."