As with the staffs of the other regiments, there are a few items of note with this one. Edwin Sumner was promoted prior to the war’s outbreak, which is why Philip St. George Cooke of the 2nd U.S. cavalry is considered the only one of the five commanders who did not resign when the war started. Before anyone gets too excited, Robert E. Lee’s promotion was only on paper. He was already in Washington when appointed colonel, and did not serve a day with the regiment before resigning the following month.
There are gaps in the positions of adjutant and quartermaster. This is unusual because by early 1863 the entire regiment was serving together. Interestingly, after 1862 all of the adjutants and quartermasters were officers who were enlisted when the war started. One of them, John Lee, was actually a sergeant in the 6th U.S. Cavalry when he received his commission. This regiment was the only one of the six cavalry regiments not to appoint a commissary during the war, though I have not been able to find an explanation for this anywhere.
Colonels
Edwin V. Sumner March 3, 1855 – March 16, 1861
Robert E. Lee March 16, 1861 – April 25, 1861
John Sedgwick April 25, 1861 – May 9, 1864
Lawrence P. Graham May 9, 1864 – December 15, 1870
Lieutenant Colonels
William J. Hardee June 28, 1860 – January 31, 1861
William H. Emory January 31, 1861 – May 9, 1861
Thomas J. Wood May 6, 1861 – November 12, 1861
James Oakes November 12, 1861 – July 31, 1866
Majors
John Sedgwick March 8, 1855 – March 16, 1861
William H. Emory May 26, 1855 – January 31, 1861
Delos B. Sackett January 31, 1861 – May 3, 1861
Thomas J. Wood March 16, 1861 – May 9, 1861
Samuel D. Sturgis May 3, 1861 – October 27, 1863
George Stoneman May 9, 1861 – March 30, 1864
Richard W. Johnson July 17, 1862 – October 12, 1867
Adjutants
A. V. Colburn February 17, 1857 – May 24, 1861
George G. Huntt September 14, 1861 – July 17, 1862
E. D. Baker November 30, 1862 – April 1, 1863
Thomas W. Sullivan August 13, 1863 – February 6, 1865
Wirt Davis March 1, 1865 – June 19, 1868
Quartermasters
John B. McIntyre April 15, 1858 – May 3, 1861
W. M. Wilson March 15, 1862 – November 30, 1862
John Lee November 30, 1862 – August 11, 1866
Sources: Heitman, pgs 33, 34