- Samuel Peter Heintzelman
- September 30, 1805
- Manheim, Pennsylvania
- Peter and Ann Elizabeth (Grubb) Heintzelman
- United States Military Academy (1826)
- Military officer
- Major General (USA)
- Major General (USVA)
- Margaret Stewart (1844)
Place of Death:
- Washington, D.C.
Date of Death:
- May 1, 1880
Place of Burial:
- Forest Lawn Cemetery, Buffalo, New York
- Samuel Heintzelman’s father was a merchant who also served as the village postmaster.
- Samuel Heintzelman entered the United States Military Academy in 1822, graduating in 1826, 17th in his class of 41 cadets.
- After graduating from the United States Military Academy, Samuel Heintzelman was commissioned as a brevet second lieutenant in the 2nd U.S. Infantry on July 1, 1826.
- Samuel Heintzelman served on quartermaster duty in Florida during the Second Seminole War (December 23, 1835 – August 14, 1842).
- Samuel Heintzelman was promoted to captain on July 7, 1838.
- Samuel Heintzelman married Margaret Stewart of Albany, New York, on December 5, 1844, at Buffalo. The marriage produced two children.
- During the Mexican–American War (April 25, 1846–February 2, 1848), Samuel Heintzelman served with General Winfield Scott’s army.
- On October 9, 1847, Samuel Heintzelman was brevetted to the rank of major for “gallant and meritorious service” in the Battle of Huamantla.
- In December 1851, Samuel Heintzelman led a campaign against the Yuma Indians. During the course of the campaign, he established Fort Yuma near the confluence of Colorado and Gila rivers.
- On March 3, 1855, Samuel Heintzelman was promoted to major of the 1st U.S. Infantry while campaigning against Indians along the Rio Grande River.
- During his time in the Southwest, Samuel Heintzelman was president of the Sonora Exploring and Mining Company, serving as director of its field operations for a brief period while on leave from the army.
- In 1859, Samuel Heintzelman led a campaign against Mexican outlaw and folk hero Juan N. Cortina, known as the First Cortina War.
- When the Civil War began Samuel Heintzelman was promoted to colonel in on May 14, 1861, and placed in command of the newly formed 17th U.S. Infantry. Three days later he was elevated to brigadier general in the volunteer army and given command of the 3rd division of the Army of Northeastern Virginia.
- Samuel Heintzelman took part in the First Battle of Bull Run on July 21, 1861. During the fighting, his elbow was shattered by a gunshot.
- Samuel Heintzelman served as commander of the 3rd Corps of the Army of the Potomac, during Major General George B. McClellan’s Peninsula Campaign.
- Samuel Heintzelman took part prominently in the Battle of Yorktown (April 5, 1862 – May 4, 1862), the Battle of Williamsburg (May 5, 1862), the Battle of Seven Pines (May 31, 1862–June 1, 1862), the Battle of Savage’s Station (June 29, 1862), the Battle of Glendale (June 30, 1862), and the Battle of Malvern Hill (July 1, 1862).
- Samuel Heintzelman was brevetted to brigadier general in the regular army for “gallant and meritorious conduct “at the Battle of Seven Pines.
- Samuel Heintzelman’s corps was transferred to Major General John Pope’s newly-formed Army of Virginia in time to take part in the Union defeat at the Second Battle of Bull Run (August 28, 1862–August 30, 1862).
- Samuel Heintzelman’s stature as a corps commander was often overshadowed by the performance of his two more celebrated divisional commanders, Joseph Hooker and Philip Kearny.
- Civil War historians generally agree that Samuel Heintzelman’s lackluster performance during the Peninsula and Northern Virginia campaigns demonstrated his shortcomings leading large numbers of soldiers.
- Samuel Heintzelman commanded the 22nd Corps, responsible for the defense of Washington, D.C., from February 2, 1863, until October 13, 1863.
- Samuel Heintzelman commanded the Northern Department, headquartered in Columbus, Ohio, from October 1863 until October 1864.
- Samuel Heintzelman retired from volunteer service on August 24, 1865, but remained in the regular army, commanding the 17th U.S. Infantry, mostly in Texas.
- Samuel Heintzelman retired from the army on February 22, 1869.
- A special act of Congress enacted on April 29 of that year, elevated Samuel Heintzelman to the rank of major general for “wounds received in the line of duty.”
- Samuel Heintzelman died in Washington, D.C., on May 1, 1880, at the age of seventy-five.
- Samuel Heintzelman is buried in Forest Lawn Cemetery, Buffalo, New York.