Much of the history of Perrin's 11th Mississippi Cavalry will be found with other commands. Here's one example, staring with the paragraph on the Spring of 1864 --
http://mississippiscv.org/MS_Units/10th_MS_Cav.htm

If you review the Official Records for the period 1864-65, the regiment's movements are largely traced through communications mentioning Ferguson's Brigade. After the surrender of Lee's army, survivors were ordered to Charlotte NC where they formed one of four Confederate cavalry brigades assigned to escort President Davis and his party south to the Savannah River.