James Mercer Garnett McGuire was born at Theological Seminary, VA, the eldest surviving son of the Rev. John Peyton McGuire (d. 1869) and his wife Maria Garnett (1808-1841). The Rev. McGuire was at one time principal of Episcopal High School in Fairfax Co., VA.
J.M.G. McGuire attended U.Va. during sessions 29-30 (1852-1854). He later graduated from the University of Pennsylvania medical school, and practiced in Berryville, VA. Dr. McGuire enlisted in the Confederate Army on 7 Jan. 1861 as an assistant surgeon, and was commissioned an officer in Company S, 1st Virginia Infantry Regiment on 1 July 1861. He was promoted to full surgeon on 15 Mar. 1863, and transferred to Company S, 33rd Virginia Infantry, on 15 Apr. 1864.
He married Elizabeth “Bettie” Holmes McGuire (d. 1874), daughter of Dr. William D. McGuire, on 26 Feb. 1864. The couple had several children: William M. McGuire (1865-1866), Maria Garnett McGuire (b. 1867) who married in 1902 William Travers Lewis, John Peyton McGuire (1869-1890), and Charles Fenton McGuire (b. 1871) who married in 1906 Margaretta McCormick. J.M.G. McGuire married secondly, on 30 Apr. 1884, Mrs. Elizabeth (Ware) Britton (b. 1838). This couple had no issue.
- Barringer, Paul B., James M. Garnett, and Rosewell Page, eds. University of Virginia: its history, influence, equipments, and characteristics. New York, 1904. Accessed via books.google.com
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- Garnett, James Mercer. Genealogy of the Mercer-Garnett family of Essex County, Virginia. Richmond, VA, 1910. Accessed via books.google.com.
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- Historical Data Systems, comp. U.S. Civil War Soldier Records and Profiles [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2009.
- Standard Medical Dictionary of North America: 1902. Chicago, IL, G. P. Engelhard & Co., 1902. Accessed via books.google.com.
- 1850-1930 U. S. Census. Virginia, in Ancestry.com. United States Federal Census [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2009.