Prior to the American Civil War (1861-1865), Robert Parker Parrott served as a captain in the US Army. From this experience, Parrott took up a position as superintendent of West Point Foundry and began design and development of several artillery pieces centered around the use of cast iron construction. The shift from bronze-barreled guns to iron-barreled guns was intriguing - artillery pieces could now be rifled internally which allowed for greater accuracy at range. Additionally, they proved lighter than comparable battlefield pieces of the time and, furthermore, iron proved plentiful in the industrialized North. Parrott's experimentation soon begat a series of field guns that were adopted by the US Army in 10-, 20-, 32-, 100-, 150-, 200-, 250- and 300-pounder forms.
The "10-pounder Parrott Rifle" featured a 2.9" bore firing a 10lb elongated projectile made exclusively for this gun. It sported an iron barrel with the typical muzzle swell encountered on competing designs. The barrel was situated atop a mounting which was coupled to a two-wheeled carriage system featuring a single tow arm. No recoil system was present so the gun moved freely backwards with each shot, forcing the crew to reposition and re-sight their cannon before firing again. Initial models were known as "Model 1861 10-Pounder Rifle". Loading was accomplished by inserting a powder charge followed by the projectile to which both were rammed down the barrel by a ramrod.
However, all of the added value apparent in bringing iron-barreled guns into operation were soon questioned. Iron proved too brittle for the inherently violent forces encountered in firing a cannon which led to breech fracturing or shattering which could (and often did) prove lethal to the gunnery crew itself (as many as eight personnel manned the weapon due to its size and weight as well as the weight of each projectile and general actions involved in efficient firing). To remedy this issue, a thick wrought iron band was developed and, while still hot and malleable, this was wrapped around the outside surface of the breech section of each gun. When cooled, these bands formed a tight, reinforced structural support at the most lethal section of the gun.
With that, Model 1861 Parrott Rifles entered a period of extensive operational service and their numbers meant that they would be used by both sides of the conflict. The 10-pounder forms were comparable to the 1857 Napoleons in the field, which proved excellent field guns during the entire conflict in their own right, though Parrott Rifles were rifled for range and lighter in overall weight making them more tactically valuable and relatively easier to manage under fire. Accuracy was strong until about 2,000 or so yards though some effectiveness could still be achieved under 3,000 yards, giving the gunnery crew great length against their enemy. Gun barrels weighed 1,750lbs alone and the 10lb projectile relied on a 2lb charge. Couple these values with the base weight of the carriage and one begins to understand the overall weights involved in maneuvering an artillery piece if this period (even those of comparable design appearing Europe at the time). A full battery of these guns could number multiple Parrott Rifles along with applicable limbers and caissons as well as supporting personnel totaling near 100 or more with cavalry units - a massive commitment of guns, man, beast and supplies.
Still, however, the issue of brittle iron persisted. Guns still shattered under stress though now the shattering occurred at the center of the barrel's length ahead of the breech bands. While not entirely reliable in service, Parrott Rifles were still available in the required numbers and their use persisted nonetheless. Gunnery crews simply dealt with the possibility of exploding barrels with each firing action and lived and died by their temperamental artillery pieces. Parrott Rifles proved multi-faceted in that they could be used along mobile battlefronts or as static fixtures in defense of key facilities. Parrott Rifles were manufactured out of the West Point Arsenal of Cold Spring, New York. Confederate factories managed to copy the type through facilities based in Georgia and appeared under the brand labels of Noble Brothers Foundry and the Macon Arsenal. Confederate versions are differentiated through their use of "Brooke" style rifling (developed by John Mercer Brooke).
10-pounder Parrott Rifles were present at the famous Battle of Gettysburg under issue to the 5th New York Battery. Targets as far out as 2,100 yards were reportedly reached with these guns and this through generally good accuracy. In 1863, Union forces adopted a 3" bore size 10-pounder Parrott Rifle and these versions soon replaced the 2.9" form. These also lost their identifiable muzzle swell form.