I discovered, thanks to a fellow SAR member, the "Supplement to the Official Records of the Union and Confederate Armies," edited by Janet B. Hewett. On pg. 198, it states that Company E of the 4th Missouri Cavalry was stationed near Little Rock, Arkansas, from July to August 1863. The unit was stationed at Camden, Arkansas, from January to February 1864, including service as provost guard at Camden. However, Pleasant Smelcer is noted on his CMSR as having deserted 10 Jul 1863. His journey home would have been to Pulaski County, Missouri. Would his journey have begun (on 10 Jul 1863) from Little Rock or from a point closer to Helena?