Gen. Isaac F. Quinby: A Math Professor Goes to War

Brig. Gen. Isaac F. Quinby

It is no secret that I spend a lot of time in the 19th century. The Victorians are endlessly fascinating and the Civil War was a defining, if incredibly destructive, moment in our history. The cast of characters in that fratricidal war also furnishes a study in character. Besides Lincoln, Gen. William Tecumseh Sherman has been one of my research interests.

It was within the ranks of Sherman’s army that I found an interesting local connection – Gen. Isaac F. Quinby. A West Point graduate and veteran of the Mexican War, Quinby was a professor of mathematics at the University of Rochester when the war began. Born near Morristown, New Jersey, in January 1821, the reticent professor looked much like his close friend Sam Grant (Ulysses).

After graduating from the Point, Quinby served as an assistant professor of natural philosophy there, high above the Hudson River.  After resigning his commission, the young teacher moved to Rochester to take up work with the University.  Nearby in Genesee County, Quinby had relatives which eased his transition to his new home.

At the outbreak of war, Quinby was quick to volunteer his services and raised a regiment of infantry – the 13th New York Volunteers.  Mustered in in May 1861, the so call “Rochester regiment” signed up for a 90 day tour of duty, Colonel Isaac Quinby commanding.

The boys from Upstate New York quickly began their association with Gen. “Uncle Billy” Sherman, serving in his brigade at the Battle of First Manassas (Bull Run).  Like much of the army, the sting of defeat after being routed on the plains of Manassas led to low morale and desertions.  Col. Quinby too suffered similar symptoms.  After a disagreement with Gen. Winfield Scott, commander of all Union armies, Quinby resigned and returned to Rochester.

In late March 1862, General Grant lured him away from the University with a commission as a brigadier general and placed him in command of the District of Mississippi, which was within Grant’s military department.  Soon Gen. Quinby was intimately involved in Grant’s effort to capture Vicksburg, Mississippi – thereby reopening the great river to Union commerce.  In September, Quinby was transferred from administrative duty to line command of the Seventh Division, Army of the Tennessee.

The Vicksburg Campaign was an exercise in frustration and patience for all involved.  Bogged down in various schemes to bypass the “Gibraltar of the West,” many soldiers and officers suffered from illness and exposure.  The big killers were dysentery and malaria.  Quinby too suffered from recurring bouts of malaria.  Finally, after many failed efforts to take or bypass Vicksburg, Grant evolved a plan to cross the river below the city and come at it from behind.  The former professor was an important part of the plan and led his troops with distinction at the Battles of Champion’s Hill and the Big Black, before taking part in the first assault on Vicksburg itself.

Vicksburg was surrendered to Gen. Grant July 4th, 1863 – just one day after Union Gen. George Meade had defeated Gen. Robert E. Lee at the Battle of Gettysburg.  Although Gen. Quinby was doubtless pleased with the great Union victory, his health continued to decline.  Quinby was assigned light duty while he attempted to recover his health.  As part of this effort, the general was ordered to Elmira, NY, where he took over command of the Draft Rendezvous Camp.  Quinby served in Elmira from July until December 1863, when he was forced to resign his commission.  Not wanting to lose his friend’s talents completely, Grant helped to secure Quinby’s appointment as Provost Marshall of the 28th Congressional District – a post he could hold simultaneously with his duties at the University of Rochester.

After the war, Quinby was appointed United States Marshall for the Northern District, a post he held until 1877.  From that time he served as a surveyor for the City of Rochester and served as a Trustee of the Soldier’s Home in Bath, NY.  This last was a source of great pride to the general, who was elected Vice President of the board in 1879 and served until shortly before his death.

General Isaac F. Quinby died September 18, 1891, in Rochester, N. Y, at the age of seventy-one.  Unfortunately, his final illness was a painful one, according to his West Point obituary.  He suffered from a combination of “pleurisy, dropsy, and an affection of the brain.”  He was survived by his wife of forty-three years, Elizabeth (nee Gardner), and eight of his twelve children.  He is buried in Hope Cemetery in Rochester.

Quinby’s grave at Mount Hope Cemetery in Rochester, NY



5 Responses to Gen. Isaac F. Quinby: A Math Professor Goes to War

  1. Thank you for bring to life one lesser know but still deeply devoted western new yorker

  2. Very interesting
    I’m his great grandson my mother being Anne Elizabeth Quinby his granddaughter. Perhaps will get to Rochester one day. Thank you.
    Arthur Noble.

  3. Thank you for this insightful piece. I am the great, great grandson of General Quinby.

Please leave a comment and join the discussion!