I believe these are two different William H. Taylors, I do not find a William Taylor in Roddy's 4th Cavalry.
William H. Taylor
Enlisted as a Private
"Ind" Co. AL Lenoir's Cavalry
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William H. Taylor
Enlisted as a Captain
"D" Co. AL 4th Cavalry
Sources used by Historical Data Systems, Inc.:
- Index to Compiled Confederate Military Service Records
- Research by James A. Dunning
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William H. Taylor, age 21, Private, Capt. Boykin’s Company of mounted men,** joined for duty and enrolled November 21, 1861 at Mobile, Ala. by Capt. Yancey for 3 years, having traveled 263 miles to place of rendezvous, value of horse $250, horse equipment $32.50, horse killed at the battle of Shiloh April 6, 1862, last recorded present December 31, 1863, receipted for an issue of clothing March 9, 1864, no further records
** This company subsequently became Lenoir’s Independent Company, Alabama Cavalry
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William H. Taylor, Captain, Capt. Taylor’s Company, Russell’s Battalion of Partisan Rangers,* enlisted July 9, 1862 at Big Spring, Mayhill Co. by Capt. Wm. H. Taylor, Ala. for 3 years or during the war, appointed Captain, Company C, 15th Battalion Partisan Rangers, Tenn. September 22, 1862, appointed to command Company D, 4th Alabama Cavalry November 12, 1862, no further records
* This company subsequently became Company D, 4th Regiment (Russell’s) Alabama Cavalry
M311: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Alabama
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4th (Russell's) Cavalry Regiment was formed at Murfreesboro, Tennessee, in December, 1862, by consolidating four companies from the 3rd (Forrest's Old) Tennessee Cavalry Regiment, six companies of the 4th Alabama Battalion, and the Russell Rangers or 15th Tennessee Cavalry Battalion. Its members were from the counties of Madison, Wilcox, Monroe, Cherokee, Jackson, Marshall, and Lawrence. It was included in the surrender on May 4, 1865.
https://familysearch.org/learn/wiki/en/4th_Regiment,_Alabama_Cavalry_(Russell's)