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Cyrus Ballou Comstock
[[Image:File:Cyrus B. Comstock.png|center|200px|border]]'
Personal Information
Born: February 3, 1831
Place of Birth: {{{place of birth}}}
Died: May 29, 1910
Place of Death: {{{place of death}}}
Birth Name: {{{birth name}}}
Other Information
Allegiance: United States of America
Participation(s): {{{participations}}}
Branch: United States Army
Union Army
Service Years: {{{service years}}}
Rank: Brevet Major General
Service number : {{{servicenumber}}}
Unit: {{{unit}}}
  • Chief Engineer, II Corps
  • Chief Engineer, Army of the Potomac
  • Chief Engineer, Army of the Tennessee
  • Chief Engineer, Department of North Carolina
Battles: American Civil War
Relations: {{{relations}}}
Other work: {{{otherwork}}}

Cyrus Ballou Comstock (February 3, 1831 – May 29, 1910) was a career officer in the Regular Army of the United States.

After graduating the United States Military Academy at West Point in 1855, Comstock served with the Army Corps of Engineers. At the beginning of the American Civil War, he assisted with the fortification of Washington, D.C. In 1862, he was transferred to the field, eventually becoming chief engineer of the Army of the Potomac. In 1863 during the Siege of Vicksburg, he served as the chief engineer of the Army of the Tennessee. The most significant phase of Comstock's career began in November 1864 when he was appointed to the staff of Lt. Gen. Ulysses S. Grant, becoming Grant's senior aide-de-camp. In 1865, Comstock was appointed the senior engineer in the assault on Fort Fisher, North Carolina, and the assault on Mobile, Alabama, both of which were successful. By the end of the war, Comstock had been promoted to brevet major general in the Volunteer Army and brevet brigadier general in the Regular Army.[1]

After the close of the war, Comstock served on the military commission for the trial of the conspirators in the assassination of President Abraham Lincoln. He was dismissed from the commission for his criticism of the proceedings.[2] Later, Comstock continued in the service of the Army Corps of Engineers and took part in several engineering projects, most particularly the Mississippi River Commission of which he was president.

Early life and education[]

Born in Wrentham, Massachusetts, to Nathan and Betsy Comstock on February 3, 1831, Cyrus Comstock attended the United States Military Academy at West Point. He graduated first in his class in 1855.[3] Following his graduation, Comstock was assigned to the Army Corps of Engineers and assisted with the design and construction of several fortifications. He also served as an instructor of engineering at West Point.

Civil War service[]

At the commencement of the Civil War, Comstock, then holding the rank of first lieutenant in the Regular Army was from West Point to Washington, D.C. He became an assistant to Brig. Gen. John G. Barnard, the engineer in charge of the fortifications of Washington and later chief engineer of the Army of the Potomac.[3]

Army of the Potomac[]

When the Army of the Potomac took the field in the spring of 1862 during Maj. Gen. George B. McClellan's Peninsular Campaign, Comstock continued to serve as Barnard's assistant. On June 1, 1862, during the Peninsular Campaign, Comstock was appointed chief engineer of the II Corps. He continued with the Army of the Potomac through the remainder of the Peninsular Campaign and through the Maryland Campaign.[4]

Maj. Gen. Ambrose Burnside succeeded McClellan and appointed Comstock the chief engineer of the Army of the Potomac. During the Fredericksburg Campaign, Comstock was faced with the difficult task of constructing pontoon bridges over the Rappahannock River. The arrival of the pontoon boats was greatly delayed and the Union troops attempting to construct the bridges were completely exposed to enemy fire. These factors made the task one of the most challenging of Comstock's career.[3]

When Maj. Gen. Joseph Hooker reorganized the Army of the Potomac in the spring of 1863, Comstock was removed as chief engineer of that army and placed in command of a battalion of engineers. In that capacity, he played an important role in the Battle of Chancellorsville, overseeing the construction of pontoon bridges over various rivers which first allowed the advance of the Army of the Potomac and later facilitated its retreat after Union forces were defeated.[3]

Siege of Vicksburg[]

After the Battle of Chancellorsville, Comstock was transferred to the Army of the Tennessee which was, at that time, involved in the Siege of Vicksburg, Mississippi, under the command of Maj. Gen. Ulysses Grant. Comstock arrived at Vicksburg in June 1863 and set to work on improving the siege works.[3] His efforts earned Grant's respect. Comstock was soon promoted to major and appointed chief engineer of the Army of the Tennessee.[1] The Siege of Vicksburg was successful, in part due to Comstock's supervision of the overall siege works, and the city surrendered to Union forces on July 4, 1863. This victory marked a major turning point in the war as the Union Army gained control of the Mississippi River. The impression that Comstock made on Grant would have a significant impact on Comstock's career later in the war.

Comstock remained with the Army of the Tennessee into the fall of 1863. On November 19, he became assistant inspector general of the Department of the Mississippi and promoted to lieutenant colonel of volunteers. He served in this role until March 1864.[1]

General Grant's staff[]

File:Gen. Ulysses S. Grant and staff of eight, recognized -- Maj. O.E. Babcock, Col. Wm. McK.Dunn, Capt. Henry W. Janes, Col. Ely S. Parker, Gen. Cyrus B. Comstock, Capt. Peter T. Hudson, Col. Michael R. Morgan, Gen. John A. Rawlins, ca. 1860 - ca.jpg

Staff of Lt. Gen. Ulysses Grant c. 1864 in a photograph by Matthew Brady. Brig. Gen. Cyrus Comstock is at the far right.

On March 12, 1864, Grant was appointed general-in-chief of the United States Army and moved his headquarters to the eastern theater in Virginia. Grant asked Comstock to come with him as his senior aide-de-camp. Grant determined to command in the field, following and directing the movements of the Army of the Potomac in a major offensive during the summer of 1864 known as the Overland Campaign. During the campaign, Comstock played a key role in coordinating the movements of the various corps of the army and personally conveying Grant's orders to the corps commanders.[3] His efforts were particularly successful during the Battle of the Wilderness for which Comstock won a commendation from Grant and a brevet promotion to lieutenant colonel in the Regular Army.[3]

Comstock was temporarily detached from Grant's staff and appointed by Grant to the post of chief engineer of the Department of North Carolina in January 1865.[1] The transfer was prompted by Maj. Gen. Benjamin Butler's failure to take Fort Fisher in December 1864. The fort was the last Confederate stronghold on the east coast. Serving under the command of Maj. Gen. Alfred Terry, Comstock assisted in planning a second and successful assault on Fort Fisher. Following this victory, Comstock was promoted to brevet colonel in the Regular Army.[1] He returned to Virginia and to his role as Grant's senior aide, but did not remain long.

In March 1865, Grant again dispatched Comstock to aid in a key siege operation—this time to Mobile, Alabama, the last Confederate stronghold on the Gulf of Mexico. There Comstock served under Maj. Gen. Edward Canby and assisted in operations leading to the surrender of Mobile after the Battle of Spanish Fort and the Battle of Fort Blakely in April 1865. While Comstock was serving in Alabama, Gen. Robert E. Lee surrendered to Grant after the Battle of Appomattox Courthouse, essentially ending the Civil War. For his service in Alabama, Comstock was promoted to brevet brigadier general in the Regular Army and brevet major general in the Volunteer Army.[1]

Post-war life[]

Military commission on the Lincoln assassination[]

In May 1865, while still serving on Grant's staff, Comstock was called to serve as one of the nine military commissioners to oversee the trial of the conspirators in the assassination of Abraham Lincoln. At first, Comstock was eager to see the prosecution of the conspirators, writing that, for them, "death is too good."[5] However, as the trial proceeded, Comstock became disturbed by the secrecy of the military proceedings. Concerned about the violation of the defendants' rights, he began to openly argue for the case to be transferred to a civilian court. Comstock was removed from the commission after his protests, ostensibly because he served on Grant's staff and, because Grant had been a potential target of the conspirators, Comstock could not be counted on to act impartially.[2]

Later work with the Corps of Engineers[]

Comstock served on Grant's staff until 1866, then returned to service with the Corps of Engineers and remained on active duty until 1895.[3] In the course of his post-war duty, he served with several boards and commissions including the Permanent Board of Engineers in New York City, the geodetic survey of the north and northwestern lakes of the United States, and was president for many years of the Mississippi River Commission.[6]

Comstock was a prominent member of the National Academy of Sciences and bequeathed a fund to the Academy to support an award to a scientist conducting innovative work in the investigation of electricity, magnetism, or radiant energy. Today known as the Comstock Prize in Physics, the award in the amount of $20,000 is granted every five years by the Academy.[7]


In 1869, Comstock married Elizabeth Blair, daughter of Montgomery Blair who had served as United States Postmaster General during the Lincoln administration.[6] They had a daughter, Elizabeth Marion Comstock, who was born in Detroit, Michigan in 1872 while Comstock was at work on the geodetic survey of the Great Lakes.

See also[]

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  • List of Massachusetts generals in the American Civil War


  1. 1.0 1.1 1.2 1.3 1.4 1.5 Bowen, 901 – 902.
  2. 2.0 2.1 Chamlee, 223.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Heidler, 475 – 476.
  4. Eicher, 181.
  5. Chamlee, 221.
  6. 6.0 6.1 "Biographical Note". C. B. Comstock Papers: A Finding Aid to the Collection in the Library of Congress. The Library of Congress. 2003. Retrieved April 24, 2010. 
  7. "Academy Honors 16 for Major Contributions to Science". News from the National Academies. The National Academies. January 16, 2004. Retrieved April 24, 2010. 


External links[]