MLA
Casey, Silas, 1807-1882. Special Orders No. 131, detailing Lieutenant Scott, previously of the 8th Independent Battery, New York Light Artillery, as Assistant to the Provost Marshall of Casey's Division, by order of Brigadier General Silas Casey. Days later, during the Battle of Seven Pines, the division, in IV Corps under Brigader General Erasmus D. Keyes, suffered enormous casualties - May 11, 1862. May 11, 1862. Civil War Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3483j9kfgv-cor.
APA, 6th edition
Casey, Silas, 1807-1882. (May 11, 1862)[Special Orders No. 131, detailing Lieutenant Scott, previously of the 8th Independent Battery, New York Light Artillery, as Assistant to the Provost Marshall of Casey's Division, by order of Brigadier General Silas Casey. Days later, during the Battle of Seven Pines, the division, in IV Corps under Brigader General Erasmus D. Keyes, suffered enormous casualties - May 11, 1862]. Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3483j9kfgv-cor.
Chicago
Casey, Silas, 1807-1882, Special Orders No. 131, detailing Lieutenant Scott, previously of the 8th Independent Battery, New York Light Artillery, as Assistant to the Provost Marshall of Casey's Division, by order of Brigadier General Silas Casey. Days later, during the Battle of Seven Pines, the division, in IV Corps under Brigader General Erasmus D. Keyes, suffered enormous casualties - May 11, 1862, May 11, 1862, Civil War Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/3483j9kfgv-cor.