The three artillery types just described were highly mobile in the field, being carried on a two-wheel carriage made of white ash with a box trail, the piece behind the gun that touches the ground. The woodwork on all the battery equipment was painted mustard.
Each gun type could fire solid shot, spherical case, and canister. These might be “fixed” round (a complete round made up of a single unit), “semi-fixed” (a round of two components), or “unfixed” (ammo where the powder charge and the projectile could be varied). Each limber to which the gun was attached for transportation carried one 600-pound ammunition chest; every two-wheeled caisson carried two. In combat the light artillery companies could fire their ordnance at a rate of one missile every 10 to 15 seconds—over five times that of their Mexican opponents.
The Men Who Serviced the Light Artillery
The light artillery companies that served in the war were officered by graduates of the U.S. Military Academy at West Point. Many of the NCOs and enlisted men had had training at either Fortress Monroe or the School of Artillery Instruction at Carlisle Barracks in Pennsylvania. The crew of a light artillery battery consisted of the following members as proscribed by a congressional act of August 1842: one captain, two 1st and one 2nd lieutenant, four sergeants, four corporals, two artificers, two musicians, and 42 privates. By 1846 the authorized enlisted-man strength for a battery was a hundred men so that the company could employ six guns. The term of service was five years for enlisted men.
Tactically, each gun in a light battery during the Mexican War was serviced by eight enlisted men. The gun commander was in charge of the piece and was responsible for aiming the cannon. A lieutenant would normally take control of two guns when they were detached from the rest of the battery. During battle the light companies would employ the practice of advancing in front of friendly troops and deliver fire on the enemy at about 1,000 yards or less. A hallmark of American light artillery tactics was the judicious use of such detachments of one or two guns to meet multiple threats from the enemy. Many times separate batteries would lend support fire to other gun units to increase the effectiveness of the fire placed on the enemy. Both of these methods were very successful at the Battles of Palo Alto (May 8,1846) and Buena Vista (February 22-23, 1847).
Mobility was key to these American tactics. Lighter guns and carriages, teams of six horses per gun, handled by well-trained soldier-drivers, made the superior armament of the Americans—and the outstanding aggressiveness of its officers—effective on any part of the battlefield at any time, in any number of fire concentrations and combinations.
During Scott’s Mexico City Campaign (March to September 1847) the light guns were of less effect due to mountainous and marshy ground. But the light artillery did good service by lending direct fire support to the infantry it was paired with when the latter had to storm strongly held Mexican positions such as at the Battles of Cerro Gordo (April 18,1847) and Chapultepec (September l3, 1847). And even in urban fighting at the Battle of Monterrey (September 20-24, 1846), 6-pounders were hauled onto rooftops to better fire at Mexican fortified positions. The presence of these off-the-ground guns hastened the surrender of the city.
Lessons Not Learned
The Mexican-American War proved that Regular Army light artillery in the service of the United States was a weapon that could obtain battlefield superiority, if not supremacy, over its enemies. Its officers proved to be masters of artillery tactics, theory, and gunnery as well as highly motivated brave young men who were not afraid to experiment with new ways to ply their trade. The aggressive use of the light artillery during the war, either in support roles or acting independently, made the difference between victory and defeat in the struggle with Mexico.
Light artillery’s use also convinced American military leaders that the offensive was more powerful than the defensive. (Artillery, even light ordnance, could still outrange the smoothbore muskets of the period.) As a result, the officers in command of the Union and Confederate armies during the War Between the States, many of whom fought in Mexico, would conduct a war between 1861 and 1865 with little understanding that the times and new weapons technology had changed the nature of warfare, and that the defense now held the upper hand. This military misapprehension would cost the nation dearly in loss of human life.
Arnold Blumberg, an attorney from Baltimore, Md., has had a long-abiding interest in military history concerning the musket and saber period.
This article first appeared on the Warfare History Network.
Image: Wikimedia Commons.