James Henry Jarrett was born in Jarrettsville, Maryland on February 23, 1832 to Luther and Julia A. Jarrett. The town was known as Carman at the time of his birth. His father was a substantial landowner there and the first postmaster, however, and the postal name of the town was changed to Jarrettsville in 1838. The younger Jarrett entered Dickinson College in Carlisle, Pennsylvania in 1849 with the class of 1852 and was elected to the Union Philosophical Society. He left the College in 1850 to enroll at the University of Maryland Medical School, where he earned his degree in 1852 and returned home to practice.
Jarrett was elected to the Maryland House of Delegates from his home area, serving one term from 1855 to 1856. When the Civil War broke out, he declared his intentions to join the Union cause, much to the consternation of his family and the local population. His younger brother, also a physician, served with the Confederate First Maryland Cavalry. Jarrett persisted, however, and mustered into Purnell's Maryland Legion as assistant surgeon in October 1861, transferring in August 1863 to the Seventh Maryland Infantry as surgeon. In December 1863, he became acting surgeon-in-chief of his division, the Third of the First Army Corps of the Army of the Potomac. He mustered out as a major on May 5, 1864.
Following the war, Jarrett did not return to Jarrettsville. From 1865 to 1869, he served in the Baltimore Customs House and eventually settled in Towson, Maryland, where he had a practice. The Towson Historical Society maintains the office he had constructed on West Joppa Road as a historical site. Jarrett was also a member of the Baltimore area United States Pensions Board from 1880 to 1885. In addition, he was one of three commissioners the state appointed in 1895 to complete a record of Union service by the men of Maryland during the war. This record was later published as the History and Roster of Maryland Volunteers, War of 1861-65, Two Volumes (1896).
In November 1852, Jarrett married Julia A. Spottswood of Carlisle, a relative of a Dickinson classmate whom he had met during his time at the College. The couple had four children, two boys and two girls.
John Osborne and James W. Gerencser, eds., “James Henry Jarrett,” Dickinson Chronicles, http://chronicles.dickinson.edu/encyclo/j/ed_jarrettJH.htm.