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John Irvin Gregg
Personal Information
Born: July 19, 1826(1826-07-19)
Place of Birth: {{{place of birth}}}
Died: January 6, 1892 (aged 65)
Place of Death: {{{place of death}}}
Nickname: Long John
Birth Name: {{{birth name}}}
Other Information
Allegiance: United States of America
Participation(s): {{{participations}}}
Branch: Cavalry, Union Army
Service Years: {{{service years}}}
Rank: Brevet Major General
Service number : {{{servicenumber}}}
Commands: Cavalry Corps of the Army of the Potomac
Battles: Mexican-American War
American Civil War
Indian Wars
Awards: {{{awards}}}
Other work: {{{otherwork}}}

John Irvin Gregg (July 19, 1826 – January 6, 1892) was a career U.S. Army officer. He fought in the Mexican-American War and during the American Civil War as a general officer in the Union army.

Early life and career[]

John Irvin Gregg was born in Bellefonte, Pennsylvania, the grandson of Andrew Gregg (a U.S. Senator from Pennsylvania) and a cousin of future Union general David McMurtrie Gregg. He was also related to Pennsylvania governor Andrew Gregg Curtin. Gregg served in the "Centre Guards," a Centre County militia unit, as a lieutenant.

During the Mexican-American War, he enlisted as a private in the 2nd Pennsylvania Infantry on December 29, 1846, and was mustered out of the volunteer service on May 6, 1847. He then received promotions to first lieutenant as of February 18, and to captain as of September 5, both in the 11th U.S. Infantry, serving as a recruiting officer. He was honorably discharged on August 14, 1848.[1]

He then entered the iron industry with the firm Irvin, Gregg & Co., owned by family members. He married Harriet Marr, the daughter of a local Presbyterian minister and schoolteacher. They had two sons, Irvin and Robert.

Civil War service[]

When the Civil War broke out, Gregg was commissioned a captain in the 3rd U.S. Cavalry on May 14, 1861. He then joined the volunteer army in June as a captain in the 34th Pennsylvania Infantry. He resigned soon afterward to accept a commission in the regular army as a captain in the 6th U.S. Cavalry. On November 14, 1862, Gregg was promoted to colonel of the 16th Pennsylvania Cavalry. He then commanded many different cavalry brigades in the various reorganizations of the Army of the Potomac.[1]

Gregg earned a brevet promotion to major on March 17, 1863, for "gallant and meritorious service" at the Battle of Kelly's Ford.[1] A month later, he was given command of a division in the cavalry corps. He led it during the Chancellorsville and Gettysburg Campaigns.

In October 1863, he earned another brevet to lieutenant colonel for the Battle of Sulphur Springs. He was wounded at the Second Battle of Deep Bottom and won a brevet again on October 7, 1864, this time to colonel in the regular army. He was promoted to brevet brigadier general of volunteers on August 1, 1864, for gallant and meritorious service in the engagement and defenses of Richmond on the Brock Turnpike and at the Battle of Trevilian Station.[1]

On April 7, 1865, Gregg was slightly wounded at the Battle of Sayler's Creek, captured the next day north of Farmville, Virginia, and was released two days later. Near the close of the war, Gregg was appointed a brevet major general in the volunteers and brevetted to brigadier general in the regular army, both effective March 13. He briefly was in command of the Cavalry Corps, Army of the Potomac from February 10 to February 24. Gregg was mustered out of the volunteer service on August 11.[1]


After the end of hostilities Gregg remained in the Army. He was named colonel of the 8th U.S. Cavalry on July 28, 1866,[1] a position his cousin David McMurtrie Gregg had desired. He then reported for duty at Camp Whipple in the Arizona Territory. He led a series of expeditions against Indians into the Mojave Desert. He was sent to the New Mexico Territory, where he commanded Fort Union from 1870 to 1872, and led efforts in that region to pursue and subdue the Apache. In 1872, he led a reconnaissance expedition to survey and map the Texas Panhandle.

Gregg retired from active service on April 2, 1879. He died in Washington, D.C., and is buried in Arlington National Cemetery in Virginia.[1]

See also[]


  • Eicher, John H., and Eicher, David J., Civil War High Commands, Stanford University Press, 2001, ISBN 0-8047-3641-3.
  • Linn, John Blair, History of Centre & Clinton Counties, Philadelphia: Louis H. Everts, Press of J.B. Lippinscott, 1883.


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Eicher, p. 267.

External links[]

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