12th Infantry Regiment
Nickname: Onondaga County Regiment; The Dozen
Mustered in: May 13, 1861
Mustered out: May 17, 1863
The following is taken from New York in the War of the Rebellion, 3rd ed. Frederick Phisterer. Albany: J. B. Lyon Company, 1912.
At the conclusion of the regiment's service in 1861, many members volunteered for further service forming the 12th militia which was later consolidated with the 12th infantry. The publications of the two regiments have not been separated.
This regiment, Col. Ezra L. Walrath, was organized at Elmira; accepted by the State for a service of two years and numbered May 8, 1861; mustered in the service of the United States, at Elmira, for three months, May 13, 1861. At the request of the general government, it was ordered by the Governor of the State, August 2, 1861, to be mustered in the United States service for the unexpired period of its term of State service. February 3, 1862, it was consolidated into five companies, A, G, H, I and K; Company B being merged into H; C into K; D into I and K; E into A; F into H. The nucleus of this regiment was of members of the 51st Regiment, State Militia, and the companies were recruited principally: A, B, C, E, H and I at Syracuse; D at Homer; F at Liverpool; G at Canastota; and K at Batavia. The regiment left the State May 29, 1861.
Colonel Henry A. Weeks received, on the return of the 12th Militia from its three months' service, authority to reorganize it for a service of three years. While the regiment as a body did not re-enter the service, a majority of the officers and enlisted men of the new organization, which was named — 12th Militia — were from the original regiment. The men were recruited principally in New York city, Patchogue and Buffalo, and mustered in the service of the United States for three years in October, November and December, 1861, and January, 1862. In January, 1862, Company A was transferred to the load N. Y. Volunteers, and the seven remaining companies of the regiment consolidated into five, B, C, D, E and F; Company G being merged into Company B, and K into E. These five companies left the State February 5, 1862.
February 8, 1862, the companies of the 12th Militia joined the battalion of five companies of the 12th N. Y. Volunteers, and completed the regimental reorganization of the latter, all the companies retaining their alphabetical designation. May 1, 1863, the two years' men were returned to Elmira and there honorably discharged and mustered out May 17, 1863; the three years' men were consolidated into a battalion of two companies, D and F, and this battalion, commanded by Maj. Henry W. Ryder, was, June 2, 1864, transferred to the 5th Veteran N. Y. Volunteers, as Companies F and E, respectively, of the latter.
The regiment served at Washington, D. C, from May 31, 1861; in the 4th Brigade, 1st Division, Army of Northeastern Virginia, from July, 1861; in Richardson's Brigade, Division Potomac, from August 4, 1861; in Wadsworth's Brigade, McDowell's Division, Army of the Potomac, from October 15, 1861; in Butterfield's Brigade, Porter's Division, 3d Corps, Army of the Potomac, from March 13, 1862; in the 3d Brigade, 1st Division, 5th Corps, Army of the Potomac, from May, 1862; the battalion as Provost Guard, 5th Corps-, from May, 1863. During its service the regiment lost by death, killed in action, 3 officers, 44 enlisted men; of wounds received in action, 22 enlisted men; of disease and other causes, 1 officer, 67 enlisted men; total, 4 officers, 133 enlisted men; aggregate, 137; of whom 4 enlisted died in the hands of the enemy.
The following is taken from The Union army: a history of military affairs in the loyal states, 1861-65 -- records of the regiments in the Union army -- cyclopedia of battles -- memoirs of commanders and soldiers. Madison, WI: Federal Pub. Co., 1908. volume II.
Twelfth Infantry.—Cols., Ezra L. Walrath, George W. Snyder, Henry A. Weeks, Benjamin A. Willis; Lieut.-Cols., James L. Graham, Robert M. Richardson, Augustus J. Root, William A. Olmstead; Majs., John Lewis, Henry A. Barnum, Augustus J. Root, Henry W. Ryder. The 12th, the "Onondaga regiment," six companies of which were recruited at Syracuse, and the others at Liverpool, Homer, Ba-tavia and Canastota, was mustered into the U. S. service for a three months' term at Elmira, May 13, 1861. It left for Washington on the 29th and upon its arrival encamped upon Capitol hill until July 10, when it was assigned to the 4th brigade 1st division of the Army of Northeastern Virginia. It was first under fire at Blackburn's ford with a loss of 34 men. It was in reserve at Bull Run, then returned to Washington, encamped at Arlington heights and was transferred to Wadswprth's brigade, McDowell's division. The 12th having been mustered into the state service for a two years' term was mustered into the U. S. service Aug. 13, 1861, for the remainder of the two years in spite of protest. In Jan., 1862, it was reorganized and made a battalion of five companies, which was stationed near Washington at Forts Ramsay, Tillinghast, Craig and Buffalo until March 21,having been joined early in February by five companies of the reorganized 12th militia. With Butterfield's brigade, Porter's division, 3d corps, the completed regiment moved via Fortress Monroe to Hampton and Yorktown; was active in the siege of Yorktown; in May was assigned to the 3d brigade, 1st division, 5th corps, with which it fought through the Seven Days' battles; was in Gen. Pope's campaign in Virginia; lost 143 men at the second Bull Run in killed, wounded and missing; was in reserve at South mountain and Antietam; fought at Fredericksburg in December, and then went into camp at Fal-mouth. The original members not reenlisted were mustered out at Elmira May 17, 1863. The three years men were formed into two companies which were transferred on June 2, 1864, to the 5th N. Y. veteran infantry. From May, 1864, the battalion of two companies served as provost guard with the 5th corps and was present through the Wilderness campaign. The total loss of the 12th was 69 deaths from wounds and 68 from other causes.
NYSMM Online Resources
Historical Sketch from the 3rd Annual Report of the Bureau of Military Statistics
"Correspondence" (Battle Of Bull's Run) - Daily Republican Advocate
From The Tribune's Special Correspondent, Camp At Berkley's Landing, Va. - Republican Advocate