Engineer Officers - Union and Confederate


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Sep 8, 2019
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In Thomas Army's Engineering Victory, he gives statistics for how many officers from the Corps of Engineers and Corps of Topographic Engineers who stayed in the Union Army and how many resigned to join the Confederate Army. He only names some of them, and not all in the same place. The book lacks an appendix listing who these officers were. My Search Fu also failed to find a list online. As such, I thought it would a good and interesting idea to compile a list of who these individuals.

Statistics given in the aforementioned book...

Corps of Engineers: 48 officers in 1861. 40 served in the Union Army - 29 as engineers and 13 as field commanders (presumably 2 started as engineers but switched later in the war). The other 8 resigned to join the Confederates; 3 remained engineers and 5 became field commanders.

Corps of Topographic Engineers: 44 or 45 officers in 1861. 37 served in the Union Army, 7 in the Confederate Army (possibly 1 resigned and sat out the war).


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Sep 8, 2019
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Note: these lists don't including officers like McClellan, Halleck, Roserans, or Ledbetter that had been Army engineers, but resigned in the 1850s only to rejoin for the war. I'll update these lists in subsequent posts as a roster is compiled.

Corps of Engineers - joined the Confederate Army
  1. Edward P. Alexander *
  2. P.G.T. Beauregard *
  3. Jeremy F. Gilmer
  4. G.W.C. Lee *
  5. W.H.C. Whiting *
  6. Robert E. Lee??? * (the book may have been counting him - can anyone confirm if he formally transferred from the Corps of Engineers to the Cavalry in the 1850s or did he retain his position in the Engineers while serving with the 2nd Cavalry in Texas?)
  7. Walter H. Stevens
  8. ???
Corps of Engineers - Union Army
  1. Orville Babcock (WP '61)
  2. John G. Barnard
  3. George W. Cullum (who later compiled Cullum's Register)
  4. Richard Delafield
  5. James C. Duane
  6. John N. Macomb
  7. James B. McPherson *
  8. James St. Clair Morton
  9. John Newton *
  10. John G. Totten
  11. Daniel P. Woodbury
  12. Horatio G. Wright *
* indicates field commander during the war.

That's only 12 of 40 identified so far, including only 3 of 13 field commanders

Topographic Engineers - joined the Confederate Army
  1. Robert F. Beckham
  2. Charles Read Collins
  3. Joseph Dixon
  4. William Holding Echols
  5. Joseph C. Ives
  6. Martin Luther Smith (field commander 1861-1863, engineer 1864-1865)
  7. William P. Smith (WP '57; I am having trouble identifying his Civil War service)
Topographic Engineers - Union Army
  1. Henry L. Abbot
  2. Hartman Bache
  3. Nicholas Bowen
  4. George Derby (on extended leave, died without serving during the war)
  5. William B. Franklin *
  6. Campbell Graham (retired in 1861 due to medical disability)
  7. Andrew A. Humphreys %
  8. George G. Meade *
  9. George H. Mendell
  10. Nathaniel Michler
  11. John G. Parke *
  12. Orlando M. Poe (engineer most of the war, except for about six months commanding the 2nd MI Infantry)
  13. John Pope *
  14. Haldiman S. Putnam *
  15. William F. Raynolds
  16. Lorenzo Sitgreaves
  17. Joseph Lee Kirby Smith *
  18. William F. "Baldy" Smith *
  19. Charles N. Turnbull
  20. Orlando G. Wagner
  21. Gouvenor K. Warren %
  22. Junius B. Wheeler
  23. Amiel W. Whipple *
  24. Robert S. Williamson
  25. James H. Wilson %
  26. Israel C. Woodruff
* served as a field commander during the war
% served as an engineer into 1862 or 1863 then became a field commander

26 of 37(?) identified so far (unclear if the book counted Derby and Graham)

Who is missing from these lists? Cullum's Register (free and searchable online) is an easy way to confirm served in 1861 and whether it was Corps of Engineers vs Corps of Topographical Engineers.
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Sep 8, 2019
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12 more Corps of Engineers, all Union:
Henry W. Benham (mostly as an engineer, but did command a brigade in 1861)
Charles E. Blunt
Cyrus Comstock
William P. Craighill
Rene E. DeRussy
John G. Foster *
Edward B. Hunt
John D. Kurtz
John C. Palfrey
Frederick E. Prime
Charles Seaforth Stewart
Godfrey Weitzel *

Brings the list to 24 of 40 identified, including 5(?) of 13 field commanders.
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Sep 8, 2019
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Found the missing Corps of Engineer officer who went CSA: Samuel H. Lockett.

More Corps of Engineers in the Union Army, bringing the list to 35 of 40 (plus 5 West Point 1861 graduates), but only 6 of 13 field commanders who I would have thought would be the easier ones to come up with.
Thomas Lincoln Casey
Charles E. Cross (WP '61)
Arthur H. Dutton (WP '61)
George H. Elliot
Francis U. Farquhar (WP '61)
Quincy A. Gillmore *
David C. Houston
Walter McFarland
William E. Merrill
Patrick J. O'Rorke (WP '61)
William C. Paine
Chauncey B. Reese
Henry M. Robert (who famously wrote Robert's Rules of Order)
George W. Snyder
John A. Tardy