37th Tennessee was organized at Camp Ramsey, half a mile north of Knoxville, on Thursday, the 10th of October, 1861. Company B (Thomas's) from Claiborne County.
On May 10, 1862 upon the re-organization of the army, Capt. Thomas was not re-elected Capt. of Company B and was dropped from the rolls.
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The 61st Tennessee was organized at Henderson's Mills in Green county, Tenn. November 10, 1862. Company H was raised from Claiborne County. James D. Thomas was appointed Adjutant of the regiment.
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James D. Thomas, appointed Adjutant, 61st Tennessee Infantry September 5, 1862, captured July 4, 1863 at Vicksburg, paroled July 8, 1863 (Footnote)
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Thomas served with the regiment through the end of the war and wrote the history of the regiment after Col. Rose was captured October 28, 1864 at Russellville. See Military Annals of Tennessee, Confederate, John Berrien Lindsley, editor, Broadfoot Publishing Co., 1995, pp. 579-581
At the Big Black River, Mississippi, May 17, 1863 " . . . Adjutant James D. Thomas voluntarily undertook to go to Gen. Vaughn's position on the field to inform him of the anticipated assault on the regiment and to obtain, if possible, reinforcements to occupy the open space in the line. . . " [More to follow, Lindsey, pp. 575-6]
Comment, the regiment was decimated in this engagement losing nearly 300 men killed, wounded, and captured. Thomas was spared and served through the remainder of the siege of Vicksburg surrendering with the army July 4, 1863.