Intermediate between the field gun and mortar was the howitzer which launched an explosive shell on a curved trajectory against enemy personnel or fortifications.

In general, a howitzer required a smaller charge than a field gun to lob a projectile of similar weight.

[1] On the other hand, by British and American convention, some howitzers were named after the field gun which had the same bore size.

Since the United States had few copper and no known tin deposits, in 1800 Secretary of War Henry Dearborn urged all cannons to be cast from iron.

[4] The final bronze Model 1841 12-pounder howitzers manufactured by Alger and Ames served the US Army for the next 27 years (i.e until 1868).

[6] The Eagle Foundry of Miles Greenwood in Cincinnati, Ohio produced 14 bronze M1841 12-pounder howitzers for the U.S. Army in 1861–62.

The Western Foundry of William D. Marshall & Co. of St. Louis, Missouri delivered 16 bronze M1841 12-pounder howitzers to the U.S. Army during the same period.

[7] Several foundries in the Confederacy manufactured an estimated 118 bronze and 66 cast iron 12-pounder howitzers during the American Civil War.

Other Confederate producers of this weapon were Quinby and Robinson (43), T. M. Brennan (26), Noble Brothers (14), Leeds (9), John Clark (7), Washington Foundry (7), Wolff (3), A.

However, because of its shorter range, the mountain howitzer filled only a minor role in the American Civil War, being used in the Western Theater.

[10] The Model 1841 bronze 12-pounder howitzer barrel was 53.0 in (134.6 cm) from the base ring to the muzzle and weighed 785 lb (356 kg).

At 5° elevation, the gun could throw the shell a distance of 1,072 yd (980 m) with the standard firing charge of 1.0 lb (0.45 kg).

[15] The Union 1864 Field Artillery Instructions and the Confederate 1863 Ordnance Manual both prescribed that each ammunition chest held 15 shells, 20 spherical case shot, and 4 canister rounds.

[18] In 1840, Secretary of War Joel Roberts Poinsett sent American officers to Europe to study artillery.

[20] The Battle of Palo Alto on 8 May 1846 was largely an artillery duel in which the American batteries inflicted disproportionate losses on the Mexican soldiers.

[21] Though most accounts state that the batteries of Ringgold and Duncan were armed with four 6-pounder guns each, an archeological study found evidence that one or more 12-pounder howitzers were used.

The next morning, the Mexican army fell back to a second position but it was beaten that day at the Battle of Resaca de la Palma.

During the action, the numerically superior Mexican army under Antonio López de Santa Anna forced many of the American volunteer units to retreat, but the artillery saved the day.

[25] George B. McClellan was part of the American Military Commission to Europe of 1856 where he observed the new French Canon obusier de 12 which incorporated the functions of both field gun and howitzer.

[26] After the First Battle of Bull Run on 25 July 1861, the Union Army in the Eastern Theater had 650 gunners manning nine batteries of mostly mixed calibers.

[27] At the Battle of Pea Ridge in the Western Theater on 6–7 March 1862, both armies were equipped with Model 1841-vintage artillery pieces and most of the weapons were organized in mixed batteries.

[32] To take one example of a Confederate unit, the 4th Battery Washington Artillery (Eshleman's) was armed with two 12-pounder howitzers and two 6-pounder field guns.