Pioneer, a privateer two-man submarine, was begun in New Orleans in 1861 to meet the menace of the United States steamers New London and Calhoun on Lake Pontchartrain. She was completed in early 1862, having been constructed from quarter-inch riveted iron plates that had been cut from old boilers.
Some reports indicate that Pioneer was built in the Leeds Foundry but her principal inventor, J. R. McClintock, stated that she was built in his Machine Shop at 21 Front Levee Street, where, in partnership with B. Watson, he manufactured steam gages and turned out "minnie balls" on a high speed machine of his own invention.
According to a post Civil War interview with McClintock, Pioneer was 30 feet long, of which a 10-foot midship section was cylindrical. From either end of the cylinder was a tapered section that gave her conical ends and resulted in a kind of "cigar shape." There was a conning tower with manholes in the top and small windows of circular glass in her sides. One man propelled the submarine by turning the manual crank of the screw and her iron ballast keel, detachable from the inside, was so heavy that it barely enabled the submarine to float on the surface with the conning tower awash. She was equipped with diving planes and was armed by a clock-work torpedo, carried on top of the submarine, and intended to be screwed into the bottom of the enemy's ship by gimlet-pointed screws of tempered steel. Actual inside measurements of Pioneer made on the spot by W. M. Robinson in 1926, were reported by him to be: length of 20 feet; maximum inside width of 3 feet, 2 inches; and a maximum depth of 6 feet.
There is little clear evidence on the operations of Pioneer. She was granted a commission as a privateer by F. H. Hatch on 12 March 1862 and the application for a letter of marque was forwarded to Richmond on 1 April 1862. Her register of commission listed J. K. Scott as Pioneer's commander, and she was described by him as 34 feet in length, 4 feet breadth, 4 feet deep; measuring about 4 tons, with round conical ends and painted black. Her part-owners were identified as J. K. Scott, R. F. Barrow (brother-in-law of H. L. Hunley), B. Watson and J. R. McClintock. A surety bond of $5,000 was put up by H. L. Hunley and his lifelong friend and college classmate, Henry J. Leovy who was then a New Orleans attorney of the law firm of Ogden and Leovy.
The application for letter of marque for Pioneer called "for authority to cruise the high seas, bay, rivers, estuaries, etc., in the name of the government, and aid said Government by the destruction or capture of any and all vessels opposed to or at war with the said Confederate States, and to aid in repelling its enemies." In an interview after the Civil War, McClintock stated Pioneer made several descents in Lake Pontchartrain and succeeded in destroying a small schooner and several rafts during experiments. Before she could attack a Union ship, Farragut captured New Orleans and she was sunk to prevent her from falling into Federal hands.
Pioneer was recovered long after the Civil War and removed to Camp Nicholls, the Louisiana Home for Confederate Soldiers. On 24 April 1957 she was transferred to her present site in the Presbytere Arcade, Louisiana State Museum, New Orleans, La. She was the forerunner of two other submarines which were built at Mobile, Ala., one the unnamed submarine sometimes called "Pioneer II" (q.v.) and H. L. Hunley (q.v.).