The index below contains references to Mississippi in the Official Records of the Union and Confederate Armies, commonly referred to as the O.R. This 129 volume set is now on line at Ohio State University and also available on DVD.
The On Line edition of the O.R. follows the numbering scheme of the original, and the index below cites the same numbering scheme. In order to find a particular entry, you will need to translate the Series, Vol., Part # to a particular serial numbered volume and check the index of the particular book to find the page number(s) of the information you're looking for.