The mortar battery at the heart of Fort De Soto carries the name of a man who never saw it and died twelve years before it was built. Colonel Theodore T.S. Laidley was one of the nineteenth-century U.S. Army's foremost authorities on guns and gunnery, a career ordnance officer whose initials are stamped on the very cannon that fired the first artillery shot at Gettysburg. When the Army named the new battery on Mullet Key in 1903, it honored a man whose whole life had been the science of the weapons that battery embodied, and who had come to Florida at the end of it.
Theodore Thaddeus Sobieski Laidley was born on 14 April 1822 in Guyandotte, Virginia, now West Virginia, the third child of John Osborne Laidley and Mary Scales Hite. He entered West Point in 1838 and graduated in 1842 ranked sixth in his class, choosing a commission in the Ordnance Department, the branch responsible for the Army's weapons, ammunition, and arsenals. It was a specialist's path, less glamorous than the cavalry or the infantry but central to everything the Army did, and the young lieutenant began the long apprenticeship of arsenal duty, serving at Watervliet in New York, the Washington Arsenal, and the Allegheny Arsenal in Pennsylvania.
When war with Mexico came in 1846, Laidley joined the forces of General Winfield Scott, serving with the small ordnance detachment that supported Scott's siege train through the Veracruz campaign. He fought with distinction. At the battle of Cerro Gordo in 1847, he was ordered, with Lieutenant Roswell Ripley, to manhandle an eight-inch howitzer into a position from which it could enfilade the Mexican line, a difficult feat that helped force the enemy's surrender. He served on through the siege of Puebla, and the letters he wrote home from Mexico were later published as a vivid record of a young officer's war.
Through the Civil War, Laidley served the Union at the technical heart of its war effort. He mustered the first nine New Jersey regiments into Federal service, then in 1862 took command of the Frankford Arsenal in Philadelphia, where he designed a new machine shop, laboratory, and rolling mill to expand wartime production. In 1864 he was given command of the Springfield Armory, the Army's great small-arms manufactory, and served as Inspector of Powder, sitting on the ordnance boards that tested an early machine gun, evaluated gun cotton, and trialed wrought-iron rifled cannon. As an inspector of artillery he had stamped his initials, TTSL, on the muzzles of the guns he passed, and one of them, a three-inch ordnance rifle now standing at the Buford monument on the Gettysburg battlefield, is remembered as the gun that opened the battle, the first Union artillery shot of 1 July 1863. The weapons Laidley inspected and perfected were quite literally present at the turning points of the war.
Laidley's influence ran beyond any single command. He was a writer on his profession, the author of standard instructional works on ordnance and on rifle practice that shaped how a generation of American soldiers were taught to shoot and how American artillery was built and handled. In 1871 he took his final command, the Watertown Arsenal in Massachusetts, responsible for the carriages, shot, and accessories of field, siege, and seacoast artillery, the very category of heavy coastal weapon that Battery Laidley would one day represent. He was promoted colonel in 1875. Poor health, which had dogged him his whole life, drove him after more than forty years' service to retire and seek a gentler climate, and he came to Florida. He died at Palatka, in the interior of the state, on 4 April 1886.
Seventeen years later, by War Department General Order No. 78 of 25 May 1903, the eight-mortar battery at Fort De Soto became Battery Laidley. It was an apt match: the name of a man who had spent his life on the science of heavy ordnance, fixed to what was in effect a giant ordnance experiment, eight of the heaviest mortars the Army possessed, buried in the sand at the mouth of a Florida bay. That those guns would never fire at an enemy, and would survive into the next century as the last carriage-mounted survivors of their kind in the continental United States, is no reflection on Laidley; it is the fate of the weapon he spent his life perfecting, overtaken by the very pace of progress he had served. In 2008 the Army Ordnance Corps inducted him into its Hall of Fame.