Brig. General Thomas W. Sweeny (USA)

Is your surname Sweeny?

Research the Sweeny family

Brig. General Thomas W. Sweeny (USA)'s Geni Profile

Share your family tree and photos with the people you know and love

  • Build your family tree online
  • Share photos and videos
  • Smart Matching™ technology
  • Free!


Thomas William Sweeny

Birthdate: (71)
Death: April 10, 1892 (71)
Place of Burial: New York, Kings, New York, United States
Immediate Family:

Husband of Eugenia Octavia Sweeny

Managed by: Private User
Last Updated:
view all

Immediate Family

About Brig. General Thomas W. Sweeny (USA)

Thomas William Sweeny (December 25, 1820 – April 10, 1892) was an Irish soldier who served in the Mexican-American War and then was a general in the Union Army during the American Civil War.

Birth and early years

Sweeny was born at Cork, Ireland, on Christmas Day, 1820. He immigrated to the United States in 1833. In 1846, he enlisted as a second lieutenant in Burnett's New York Volunteers, and fought under General Winfield Scott in Mexico. At the Battle of Cerro Gordo, Sweeny was wounded in the groin. During the Battle of Churubusco, he was seriously wounded to his right arm, causing it to be amputated. For his heroics, his fellow servicemen nicknamed him "Fighting Tom". Despite this possible career-ending injury, he continued serving with the 2nd US Infantry until the outbreak of the Civil War. From 1850 to 1853, Sweeny played prominent role in the Yuma War, where he fought in several small engagements against native Americans.

Civil War

At the outbreak of the Civil War, Sweeny was in command of the arsenal at St. Louis, Missouri In reply to efforts of Confederate sympathizers to induce him to surrender that important post, he declared that before he would do so, he would blow it up. As second in command, he participated in the capture of Camp Jackson in May 1861 and later assisted in organizing the Home Guards. He was chosen as the brigadier general of that organization.

Sweeny commanded the Fifty-second Illinois at Fort Donelson. At Shiloh, in command of a brigade, he successfully defended a gap in the Union line. He returned to command his regiment but returned to brigade command when General Pleasant A. Hackleman was killed at Corinth. He commanded the Second Division of the Sixteenth Army Corps in the Atlanta campaign. At the Battle of Atlanta Sweeny's division intercepted John B. Hood's flank attack. Sweeny got into a fistfight with his corps commander, General Grenville M. Dodge, when Dodge broke protocol and personally directed one of Sweeny's brigades during the fight. Sweeny received a court-martial for these actions but was acquitted.

In 1866, he commanded the ill-fated Fenian invasion of Canada, after which he was arrested for breaking neutrality laws between the United States and Britain, but was soon released. He retired from the Regular Army in 1870 as a brigadier general.

Sweeny retired to Astoria on Long Island. He died there on April 10, 1892, and is buried in Green-Wood Cemetery in Brooklyn.


Capt. Thomas W. Sweeny, Second Infantry, acting inspector-general, for gallant and highly meritorious services, especially distinguished for his zeal in rallying broken fragments of varions regiments and in leading them into the hottest of the light.

From Gen. J. C. Fremont report after the Battle of Wilson's Creek., page 56.


Civil War Union Brigadier General. Born in Ireland, he moved to America in 1832 and settled in New York City. He joined the Baxter Blues, militia company in 1843, his unit fought in the Mexican War and his right arm was amputated after being wounded. After he recuperated, he fought against Native Americans in the Southwest and on the Great Plains. When the Civil War began, he was stationed in St. Louis, Missouri and became Brigadier General of Missouri's volunteers. While fighting at Wilson's Creek, he was wounded, carried off the field and returned to action in January of 1863. He led troops at Fort Donelson, was wounded at Shiloh, fought at Corinth and led a division in the Atlanta Campaign. After the war, he remained in the Army and retired a Brigadier General of Regulars in May, 1870. (bio by: John "J-Cat" Griffith)

Burial: Green-Wood Cemetery Brooklyn Kings County New York, USA Plot: Section 163, Lot 14257 GPS (lat/lon): 40.64929, -73.98627 Find a grave:

view all

Brig. General Thomas W. Sweeny (USA)'s Timeline

December 25, 1820
April 10, 1892
Age 71
April 10, 1892
Age 71
New York, Kings, New York, United States