In 1845, Hébert resigned from the army[1] after being appointed Chief Engineer of the State of Louisiana by Governor Alexandre Mouton. He was reappointed by Governor Isaac Johnson in 1846, but he resigned in March, 1847 to fight in the Mexican–American War.
He ran as a Democrat for the State Senate in 1849. He lost the election by nine votes. Following this he returned to his sugar plantation in Iberville. In 1851, Governor Joseph Marshall Walker appointed Hébert a delegate to the Industrial Exhibition in London.
The next year, a division among Iberville Parish Whigs gave him a seat at the 1852 Louisiana Constitutional Convention which adopted a new state constitution that was strongly pro-Whig. As a result, Governor Walker resigned early and an election was called. Since John Slidell, the leader of one faction of Louisiana Democrats was focusing on his campaign for the U.S. Senate, the Democrats turned to Hébert as their nominee for governor. He campaigned against some features of the new constitution, called for internal improvements, reform of the state militia, a banking system by general laws and redemption in specie of all paper money. Running against Judge Bordelon, a Whig from St. Landry Parish, Hébert garnered 17,334 votes to Bordelon's 15,781.
Term as governor
Hébert took the oath as Governor and guided the legislature towards improvements in water commerce and railroad construction. He also established the Louisiana Seminary of Learning at Alexandria which would later become Louisiana State University. Hébert also instituted a state library, reorganized the militia, improved Charity Hospital and organized the efforts against yellow fever of 1853.
Nationalism and the rise of the Know Nothing Party or American Party was a feature of Louisiana politics in the 1850s. Whig newspapers tried to discredit Hébert by starting rumors of his allegiance with the Know Nothings. He still appointed some Whigs to minor offices and some Know Nothings to lucrative posts. He was considered very independent in his appointments and many Democrats were disenchanted with him toward the end of his administration. Hébert was mentioned as a possible candidate for the U.S. Senate, but John Slidell was not vulnerable to an intraparty challenge.
During his administration Hébert saw four major railroads incorporated in Louisiana including the New Orleans, Jackson and Great Northern Railroad. Hébert sought to connect every part of Louisiana to New Orleans by rail. He also built levees and sought land reclamation projects. In 1855, Hébert promoted and the legislature passed a tax of on all property to support the public school system which is open only to whites between the ages of six and sixteen. With his term at an end, Governor Hébert retired to his plantation as a planter.
Civil War
With rising tension between North and South, President Abraham Lincoln was elected in December, 1860. Governor Thomas Overton Moore appointed Hébert to the military board to reorganize militia and defenses in the New Orleans area. He was appointed as a colonel of the 1st Louisiana Artillery. After secession on April 1, 1861, Hébert was appointed a brigadier general in the Louisiana Militia. In August, he was commissioned a brigadier general in the Provisional Army of the Confederacy but was not given an active position. Later he would have a command of Louisiana troops and in the Trans-Mississippi Department. Also on May 21, 1861, his first wife Marie Coralie Hébert died. He later married Penelope Lynch Andrews, daughter of John Andrews of Iberville Parish.
In 1862, General Hébert was posted to the Department of Texas. Jefferson Davis dismissed him as military commander of Texas on October 10 for imposition of martial law and harsh measures in enforcing conscription.[2][3][4] He later participated in the defense of Vicksburg. He saw battle in June, 1863, at the Battle of Milliken's Bend in Louisiana. After that, he was again posted in Texas, where he was at the time the war ended. Hébert returned to his Louisiana plantation and received a pardon from President Andrew Johnson.
Postwar
He was active in the politics of Reconstruction supporting the Liberal Republican movement and accepted a minor appointment in New Orleans. In 1872, Hébert endorsed Horace Greeley and opposed the Louisiana "Custom House" Republican faction. He supported Republican Governor Henry C. Warmoth. Governor William P. Kellogg appointed him to the Board of State Engineers in 1873 and the Board of U.S. Engineers for Mississippi River Commission in 1874.
In the presidential election of 1876, Governor Hébert changed political allegiance back to the Democrats. He died on April 29, 1880, and was buried in St. Paul Cemetery in Bayou Goula, Louisiana. Encroachment of the Mississippi River caused many individuals to be reinterred. Governor Hébert's remains, and those of his first wife, Marie Coralie Hébert, were interred at St. Raphael Cemetery in Point Pleasant, near Plaquemine, LA.