Pierre Gustave Tontant Beauregard, an American general, born near New Orleans about 1817. He graduated at West Point in 1838. In the Mexican war he earned the brevet rank of captain at Contreras and Churubusco, and of major at Chapultepec, where he was twice wounded. In 1853 he was made captain in the corps of engineers. From 1849 to 1860 he was stationed mainly at New Orleans, where he had the general charge of the construction of the mint, custom house, and marine hospital, as well as of the engineering operations on the lower Mississippi and the gulf. In January, 1861, he was appointed superintendent of the military academy at West Point; but in less than a month he resigned his commission in the army, and received the rank of brigadier general from the southern confederate government. He conducted the attack upon Fort Sumter, and was afterward sent to Virginia, where he virtually commanded at the battle of Bull Run; Gen. J. E. Johnston, who outranked him, having just come upon the field, and adopting his plan of operations.

In the spring of 1862 he was sent to the west as second in command of the department of Tennessee. Gen. A. S. Johnston having been killed early in the battle of Shiloh, or Pittsburgh Landing, April 6, Beauregard took the command, and gained a considerable success; but the next day, Gen. Buell having in the night joined Gen. Grant, he was worsted and forced to abandon the field. He retired to the fortified position at Corinth, which he strengthened and held against Gen. Ilalleck to the end of May. His health soon after failing, he was for a time relieved from active service, but was afterward placed in command at Charleston, which he successfully defended throughout the year 1863, repelling the attacks under Gen. Gillmore and Admiral Dahlgren. In 1864, when Grant was approaching Richmond, Beauregard held Petersburg until the arrival of Lee at Richmond, speedily checking the advance of Gen. Butler. In the autumn of 1864 he was placed in command of the department of the west, and made strenuous but unavailing efforts to prevent Sherman's march to the sea.

After the close of the war, in which he attained the highest rank in the confederate service, that of full general, he took up his residence at New Orleans.