Robert Parker Parrot was born on October 5, 1804 in Lee, Strafford County, New Hampshire, United States. He was of English descent and was the eldest son of a prominent ship-owner of Portsmouth, New Hampshire, who served one term as United States senator, John Fabyan Parrott. His mother, Hannah Skilling (Parker) Parrott, was the daughter of Robert Parker of Kittery, Maine, a ship-builder and commander of privateers during the Revolution.
Robert Parker Parrott attended the Daniel Austin school in Portsmouth and on July 1, 1820, entered the United States Military Academy at West Point, from which he graduated in 1824, third in a class of thirty-one.
Robert Parker Parrot was appointed second lieutenant and assigned to the 3rd Artillery. Ordered immediately to duty at the Military Academy, he served there for five years as assistant professor of natural philosophy. Following two years of garrison duty at Fort Constitution, near Portsmouth, New Hampshire, he was promoted to first lieutenant and transferred to Fort Independence, Boston Harbor, Massachussets, remaining on duty there until 1834, when he was assigned to ordnance duty. After a short staff service in military operations in the Creek Nation, he was promoted to captain of ordnance January 13, 1836, and ordered to Washington as assistant to the chief of the bureau of ordnance. Not long after beginning the duties of this assignment he was detailed as inspector of ordnance in construction at the West Point Foundry, Cold Spring, New York. His ability and expert knowledge attracted the attention of Gouverneur Kemble, president of the West Point Foundry Association, who induced Parrott to resign from the army and become superintendent of the foundry.
His resignation went into effect October 31, 1836. Three years later he succeeded Kemble as lessee of the foundry. In order to supply it with charcoal pig-iron, he purchased a tract of 7, 000 acres in Orange County, New York, and the Greenwood iron furnace, which he operated in partnership with his brother Peter. For almost forty years thereafter Parrott directed these enterprises and at the same time continued his studies of ordnance. He kept himself well informed on the world's activities in this field and, in addition, prosecuted a course of research and experiment of his own. This work covered a rather wide range at first, but upon learning of the secret production in 1849 of a serviceable rifled cannon by Krupp in Germany, he concentrated his attention on rifled ordnance.
For upwards of ten years he continued his experiments, his aim being to produce an efficient rifled cannon, simple in construction and cheap. Eventually he patented, October 1, 1861, a design for strengthening a castiron cannon with a wrought-iron hoop shrunken on the breech. The unique feature of the invention was the hoop, which was formed of a wrought-iron bar of rectangular section coiled into a spiral and welded into a solid ring. He also devised and patented, August 20, 1861, an improved expanding projectile for rifled ordnance. The expanding device was a brass ring cast upon and secured to the projectile but susceptible of being expanded into the cannon grooves by the action of the explosive gases. These inventions Parrott offered to the government at cost price, and with the beginning of the Civil War he received large orders for both guns and projectiles. "Parrott guns" were present in the field at the first battle of Bull Run and thereafter in every important engagement both on land and sea. They were made by the thousands and in many calibers, and threw "Parrott projectiles" of from 10 to 300 pounds. It is recorded that "the 200 and 300 pounder Parrott guns were the most formidable service guns extant in their time".
Furthermore, their endurance was far in excess of that required of the contemporary rifled cannon of Europe. With the termination of hostilities, Parrott ceased gun manufacture at the West Point Foundry and in 1867 withdrew from active connection with it. He and his brother continued, however, the operation of the Greenwood furnaces and property until 1877, when Parrott sold his share to his brother and retired. During this latter period he continued his experimental work and invented several improvements in projectiles and fuses. He and his brother also began in 1875, the first commercial production of slag wool in the United States. Parrott held one public office, that of first judge of the court of common pleas for Putnam County, New York (1844 - 1847), an appointment made, no doubt, because of his widely recognized uprightness and sagacity. Robert Parker Parrott died on December 24, 1877 in Cold Spring.
Robert Parker Parrott was the inventor who developed the rifled cannon known as the Parrott gun, the most formidable cannon of its time. His guns, available in a variety of sizes and mounts, were in high demand during the Civil War and were a key factor in the Union's victory. His later inventions included the Parrott Sight and the Parrott Fuse.
In 1839 Robert Patker Parrott married Mary Kemble, sister of Gouverneur Kemble and sister-in-law of James K. Paulding. At the time of his death, in Cold Spring, he was survived by his widow and an adopted son.
