Thomas William Sweeny

Background

Thomas William Sweeny was born on December 25, 1820 in County Cork, Ireland, the son of William and Honora (Sweeny) Sweeny.

Career

Thomas Sweeny emigrated to the United States in 1832. About 1843 he joined the "Baxter Blues" of New York City, and in 1846 became second lieutenant of New York volunteers in the Mexican War. He was with General Scott from Vera Cruz to the capture of Churubusco, where he received a wound that necessitated the amputation of his right arm.

Following the war, as lieutenant in the 2nd United States Infantry, Sweeny was engaged almost continuously in operations against the Yuma Indians of the Southwest or the Sioux of the Nebraska region until January 1861, when he was promoted captain and ordered to the federal arsenal at St. Louis.

After serving under General Nathaniel Lyon in the capture of Camp Jackson, Sweeny was commissioned brigadier-general of the three months' Missouri volunteers, May 20, 1861, and sent with Franz Sigel into Southwest Missouri to prevent the junction of the state troops under General Sterling Price and Governor C. F. Jackson with the Confederate army under General Ben McCulloch. Sigel's rash attempt with 1, 100 men to stop Jackson's 4, 000 at Carthage resulted in a rout, and the expedition failed of its objective.

On August 14, 1861, four days after receiving a severe wound in the battle of Wilson's Creek, Sweeny was mustered out of the Missouri volunteers, but he returned to the volunteer service as colonel of the 52nd Illinois on January 21, 1862, and under Grant aided in the capture of Fort Donelson.

He was commissioned brigadier-general of volunteers November 29, 1862, and was honorably discharged from the volunteer service in August 1865. As the result of a quarrel with his superior officer, General G. M. Dodge, after the battle of Atlanta, Sweeny was arrested and court-martialed, but acquitted.

On December 29, 1865, he was dismissed from the army for absence without leave, but on November 8, 1866, was reinstated.

An ardent Irish partisan, he was made secretary of war of the "Irish Republic" when William R. Roberts was elected president by the Fenian Congress in 1865. With Roberts he urged that Canada be conquered as a step toward freeing Ireland, and in 1866, superintended the details of the invasion of June 1-2 at Niagara and the simultaneous attempts to cross the border at Potsdam, New York, and St. Albans, Vermont. The "invasion" was a fiasco. Sweeny, with some others, was arrested by United States authorities but was soon released without trial, and thereafter his interest and influence in the Fenian movement declined. Following this interlude he returned to the regular army until his retirement in 1870 with the rank of brigadier-general.

He died at his home in Astoria, Long Island, survived by his second wife, three sons, and a daughter.

Achievements

• Thomas 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. Sweeny kept the field until the close of the fight, exciting the admiration of the whole army. 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. Thomas Sweeny was given outstanding credit by Sherman for helping save the day at Shiloh, April 6, and rendered praiseworthy service in the battles of Corinth, October 3-4, 1862, Kenesaw Mountain, June 27, 1864, and Atlanta, July 20-22, 1864. While out of the service he received much notoriety as the leader of the ill-starred Fenian raid on Canada in 1866.

Works

More photos

• book

  • Captain Thomas Cook (1752-1841), a soldier of the Revolution

    (This book was digitized and reprinted from the collection...)

  • Journal of Lt. Thomas W. Sweeny 1849-1853 (Great West and Indian Series)

Personality

Although a quick thinker and an aggressive fighter, Sweeny apparently lacked coolness and sound judgment.  

Connections

Thomas Sweeny was married twice: first, to Eleanor Swain Clark of Brooklyn, and second, to Eugenia Octavia Reagan of Augusta, Georgia.

Father:

William Sweeny

Mother:

Honora (Sweeny) Sweeny

1st wife:

Eleanor Swain Clark

2nd wife:

Eugenia Octavia Reagan

associate:

Grenville Mellen Dodge

General Union army officer on the frontier and pioneering figure in military intelligence during the Civil War.

References

• The Fight for Missouri: From the Election of Lincoln to the Death of Lyon
• Troublous Times in Canada A History of the Fenian Raids of 1866 and 1870
• Through American and Irish Wars: The Life and Times of General Thomas W Sweeney 1820-1892 (Irish Abroad)