Oliver's (McD.) Artillery. See Eufaula Artillery.

O'Neal's (William P.) Infantry. See Tennessee Troops, Confederate, 32nd Regiment.

Opdycke's (Emerson) Infantry. See Ohio Troops, 125 Regiment.

Orcutt's (Benjamin F.) Infantry. See Michigan Troops, 25th Regiment.

Orleans Guard Artillery. See Louisiana Troops.

Orleans Home Guards Infantry. See Indiana Troops.

Orleans Light Horse. See Louisiana Troops (Cavalry.

Osborne's (Milton A.) Artillery. See Indiana Troops, 20th Battery.

Owen's (W. P.) Cavalry. See H. M. Ashby's Cavalry.

Paddock's (Byron D.) Artillery. See Michigan Troops, 6th Battery.

Palmer's (John B.) Infantry. See North Carolina Troops, 58th Regiment.

Palmer's (William J.) Cavalry. See Pennsylvania Troops, 15th Regiment.

Parkhurst's (John G.) Infantry. See Michigan Troops, 9th Regiment.

Patrick's (Mathewson T.) Cavalry. See Iowa Troops, 5th Regiment.

Patterson's (James W.) Artillery. See Ohio Troops, 21st Battery.

Patterson's (Josiah) Cavalry. See Alabama Troops, 5th Regiment.

Pearce's (John S.) Infantry. See Ohio Troops, 98th Regiment.

Pearcy's (J. L.) Artillery. See H. L. W. McClung's Artillery.

Pease's (W. H.) Artillery. See Ohio Troops, 1st Regiment, Battery D.

Perkins' (George T.) Infantry. See Ohio Troops, 105th Regiment.

Perry's (M. S.) Infantry. See Florida Troops, 7th Regiment.

Persons' (A. W.) Infantry. See Georgia Troops, 55th Regiment.

Phillips' (John C.) Artillery. See Illinois Troops, 2nd Regiment, Battery M.

Phipps' (F. L.) Cavalry. See Tennessee Troops, Confederate, 12th Battalion.

Pickands' (James) Infantry. See Ohio Troops, 124th Regiment.

Pickens' (William C.) Cavalry. See Tennessee Troops, Union, 3rd Regiment.

Pickett's (George B.) Engineers. See Confederate Troops, Regulars.

Piepho's (Carlo) Infantry. See Ohio Troops, 108th Regiment.

Pierce's (Ehenezer W.) Infantry. See Massachusetts Troops, 29th Regiment.

Pierson's (William S.) Infantry. See Hoffman's Infantry.

Pioneer Brigade. See Union Troops; also James St. C. Morton and Patrick O'Connell.

Platter's (John A.) Cavalry. See Indiana Troops, 4th Regiment.

Porter's (George C.) Infantry. See Tennessee Troops, Confederate, 6th and 9th Regiments.

Powers' (Oliver M.) Cavalry. See Indiana Troops, 3rd Regiment.

Prather's (John S.) Cavalry. See Confederate Troops, Regulars, 8th Regiment.

Pressley's (James F.) Infantry. See South Carolina Troops, 10th and 19th Regiments.

Presson's (William A.) Infantry. See Illinois Troops, 73rd Regiment.

Price's (Samuel W.) Infantry. See Kentucky Troops, Union, 21st Regiment.

Printup's (D. S.) Infantry. See Georgia Troops, 55th Regiment.

Pritchard's (E. E.) Artillery. See Georgia Troops.

Provost Battalion, Atlanta. See G. W. Lee.

Purington's (George A.) Cavalry. See Ohio Troops, 2nd Regiment.

Pursifull's (James A.) Cavalry. See Kentucky Troops, Confederate.

Raffen's (Alexander W.) Infantry. See Illinois Troops, 19th Regiment.

Raum's (W. C.) Cavalry. See Mississippi Troops.

Ray's (Daniel M.) Cavalry. See Tennessee Troops, Union, 2nd Regiment.

Raymond's (Samuel B.) Infantry. See Illinois Troops, 51st Regiment.

Reeve's (Felix A.) Infantry. See Tennessee Troops, Union, 8th Regiment.

Reeves' (W. N.) Artillery. See Hilliard's Legion.

Reichard's (August) Infantry. See Louisiana Troops, 20th Regiment.

Reid's (John C.) Infantry. See Alabama Troops, 28th and 34th Regiments.

Reilly's (James W.) Infantry. See Ohio Troops, 104th Regiment.

Renwick's (George W.) Artillery. See Elgin Artillery.

Reynolds' (D. H.) Mounted Rifle's. See Arkansas Troops, 1st and 2nd Regiments (Rifles).

Reynolds' (F. A.) Infantry. See North Carolina Troops, 39th Regiment.

Reynolds' (H. A.) Infantry. See Mississippi Troops, 30th Regiment.