John Slidell, U.S. Senator

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John Slidell

Birthdate: (78)
Birthplace: New York, NY, USA
Death: July 26, 1871 (78)
Cowes, Isle of Wight, England, United Kingdom
Place of Burial: Paris, France
Immediate Family:

Son of John Slidell and Margery May Slidell
Husband of Maria Mathilde Slidell
Father of Marguerite Mathilde d'Erlanger; Marie Rosine de St. Roman and Alfred Slidell
Brother of Jane Perry; Thomas Slidell and Alexander Slidell Mackenzie

Occupation: Merchant, Lawyer, Politician, legislator, and Confederate diplomat
Managed by: Private User
Last Updated:

About John Slidell, U.S. Senator

John Slidell (1793 – July 9, 1871) was an American politician, lawyer and businessman. Originally a native of New York, Slidell moved to Louisiana as a young man and became a staunch defender of southern rights as a U.S. Representative and Senator.

Early life

He was born to the merchant John Slidell and the former Margery Mackenzie, a Scot. He graduated from Columbia University (then College) in 1810. In 1835, Slidell married the former Mathilde Deslonde, and they had three children, Alfred Slidell, Marie Rosine (later comtess de St. Roman), and Marguerite Mathilde (later baronness Frederic Emile d'Erlanger).

Merchant, lawyer, politician

Slidell was in the mercantile business in New York before he relocated to New Orleans. He practiced law in New Orleans from 1819-1843. He was the district attorney in New Orleans from 1829-1833. He also served in the state's House of Representatives. Though he lost an election to the United States House in 1828, he was elected in 1842 and served a term and a half from 1843–1845, as a Democrat. He served as minister plenipotentiary to Mexico from 1845-1846.

Prior to the Mexican-American War, Slidell was sent to Mexico, by President James Knox Polk, to negotiate an agreement whereby the Rio Grande would be the southern border of Texas. He also was instructed to offer, among other alternatives, a maximum of $30 million for California by Polk and his administration. Slidell hinted to Polk that the Mexican reluctance to negotiate might require a show of military force by the United States. Under the guidance of General Zachary Taylor, U.S. troops were stationed at the U.S./Mexico border, ready to defend against Mexican attack. The Mexican government rejected Slidell's mission. After Mexican forces attacked at Matamoros the United States declared war on Mexico on May 13, 1846.

Slidell was elected to the Senate in 1853 and cast his lot with other pro-Southern congressmen to repeal the Missouri Compromise, acquire Cuba, and admit Kansas. In the 1860 campaign Slidell supported Democratic presidential candidate John C. Breckinridge, but remained a pro-Union moderate until Abraham Lincoln's election pushed the Southern states into seceding. At the Democratic Convention in Charleston, South Carolina, in April 1860, Slidell plotted with "Fire-Eaters" such as William Lowndes Yancey of Alabama to stymie the nomination of the popular Northern Democratic Senator Stephen A. Douglas of Illinois.

Civil War

With the passage of the Louisiana ordinance of secession, Slidell resigned from the U.S. Senate and headed home. In a dramatic farewell address, he threatened the boycott of all northern manufacturing and predicted the dominance of southern ships on the seas. He argued that foreign countries would prevent the Union from blockading southern ports: "This will be war, . . . and we shall meet it with . . . efficient weapons." Despite the looming war, the historian John D. Winters reports that many Confederates "still thought a peaceful solution could be found. Many believed the Yankee incapable of learning to use a gun or of mustering enough courage to fight; the emergency [they mistakenly thought] would soon dissipate."

Slidell soon accepted a diplomatic appointment to represent the Confederacy in France. John Slidell was one of the two CSA diplomats involved in the Trent Affair in November 1861. After having been appointed the Confederate States of America's commissioner to France in September, 1861, he ran the blockade from Charleston, South Carolina, with James Murray Mason of Virginia. They then set sail from Havana on the British mail boat steamer RMS Trent, but were intercepted by the U.S. Navy while en route and taken into captivity at Fort Warren in Boston. After the resolution of the Trent Affair, the two diplomats set sail for Europe on January 1, 1862.

John Slidell was a brother of Alexander Slidell Mackenzie, a naval officer who commanded the USS Somers on which a unique event occurred in 1842 off the coast of Africa during the Blockade of Africa. In that incident, three crewmen were hanged after being convicted of mutiny at sea. Mackenzie reversed the order of his middle and last names to honor a maternal uncle.

Another brother, Thomas Slidell, was chief justice of the Louisiana Supreme Court. He was also the brother-in-law of the American naval Commodore Matthew C. Perry, who was married to Slidell's sister, Jane. Perry is remembered for opening United States trade with Japan in 1853.

Later life

Slidell moved to Paris, France, after the Civil War. He died in Cowes, Isle of Wight, England, at age 78. He is interred in the Saint-Roman family private cemetery near Paris. He, Judah P. Benjamin and A. Dudley Mann were among the high-ranking Confederate officials buried abroad.


The city of Slidell in St. Tammany Parish, Louisiana was named in his honor by his son-in-law Baron Frederick Emile d'Erlanger; the village of Slidell, Texas is also named after him.

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John Slidell, U.S. Senator's Timeline

New York, NY, USA
November 19, 1842
Age 49
New Orleans, Orleans Parish, Louisiana, United States
July 26, 1871
Age 78
Cowes, Isle of Wight, England, United Kingdom
Paris, France