 Complete the following phrase:  Following the Corinth Campaign, the regiment was reassigned to General Martin E. Greens brigade, in the Confederate Army of Mississippi, Department of Mississippi and East Louisiana. Part of Greens brigade, including many from the 20th Arkansas was captured and Major Robertson was killed in the Battle of Big Black in rear of Vicksburg on May 17, 1863. The remts of the regiment fell back inside the works and endured the forty plus day 