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Alamo Cannon Project

Ealy image of the Alamo, c 1858

The Collection

            On October 2, 2017, the Commissioner of the Texas General Land Office announced that Texas A&M University's Conservation Research Laboratory (CRL) would conserve nine cannon from the Alamo's collection. Of these nine cannon, seven are believed to have been present at the 1836 battle. Some of the cannon in the collection were discovered around the Alamo complex between 1852 and 1908. Some were found buried in the ground, while others were observed to be scattered on the surface. Two of the nine cannon in the Alamo collection, which were not from the Alamo event (but from the same period), will also be conserved.

Cannon 2475

Cannon of this period were largely classified by the weight of the shot they fired. Among the seven cannon believed to be from the event are two iron 3-pounders, two bronze 4-pounders, one iron 16-pounder, one iron 12-pounder, and an iron swivel gun. The two donated cannon are an iron 4-pounder and an iron 6-pounder.



            It appears that the only method previously used to preserve the cannon was the application of paint during the twentieth century. Although this may have been aesthetically pleasing, it did not preserve the metal for the long-term. This is why conservators at the Texas A&M University CRL are applying other, more effective methods to ensure that these cannon will last for future generations to enjoy and learn about.

            To stabilize the iron in the cannon and to remove corrosion products (and the thick layers of old paint), conservators are subjecting them to a process called electrolytic reduction.

After Electrolysis

This process sends a negative electric charge to the artifact (cathode) and a positive charge to sacrificial metal (anode), which are both submerged in an electrolyte solution (5% sodium hydroxide). The cannon remain in electrolysis up to 4 weeks, after which they are rinsed in boiling water to clean any residual chemicals from their surfaces.

Lowering the Cannon into the Boil vat

Next, the cannon are covered in tannic acid to help stabilize the surface layer of metal, and then sealed with an industrial-grade black paint to prevent any moisture from reacting with the metal.

            Some of the cannon need additional attention. The bores can be especially challenging to clean, with dirt, rocks, modern trash, and even unfired cannon balls found inside!

AC1 Bore

As of now, four of the nine cannon have been conserved and returned to the Alamo. Another two are in the final stages of conservation (tannic acid application and painting), and the small swivel gun is currently undergoing electrolysis.



            The Texas A&M conservators are also in the process of researching the Alamo cannon collection. It is hoped that this research will help establish the origin and identity of the guns, as well as confirm that seven of the cannon were used during the Alamo battle. To help determine these factors, the CRL team examines the bare metallic surface (electrolytic reduction) for any markings that could reveal additional information about the cannon.

The CRL researchers are also working with expert Ruth Brown (from "Basiliscoe") to analyze the size, shape, and band patterning of the cannon and to place them within a manufactural context.

            Of the four cannon and one swivel gun analyzed thus far, three cannon and the swivel are suspected to be from the Alamo event, and one cannon (1842 Rio Grande) was donated. The donated one is in fairly good condition and still bears some of its maker's marks. One of the most prominent marks is a cast letter B on the right trunnion.

Rio Grande - Bersham

This mark is of the Bersham ironworks in northern Wales. The cannon is a shorter 6-pounder (around 4.5 feet long) and was not a gun originally made for government service, as there was no royal badge or other official markings observed on the barrel. This particular 6-pounder was probably cast in the late eighteenth century.

            The other three analyzed cannon are in poorer condition. They have no visible markings, as their bands and original surfaces are much less defined, and each of their trunnions and cascables is broken off. The broken features are not from corrosion but from damage done by Santa Anna's soldiers after they had captured the Alamo fortification.

Cannon 2476

Not only did the Mexican forces render these cannon inoperable by removing the cascables and trunnions, they also "spiked" the guns by driving a nail through their touch holes. However, the muzzle shape and band spacing of the cannon reveal that AC1, a 4-pounder, likely came from the British Isles; Cannon 2476, either a 3- or 4-pounder, probably was cast in Sweden (a large exporter of casted guns); and the 2- or 3-pounder, Cannon 2475, has features that suggest that it came from either a Swedish or a French ironworks. The swivel gun is either a 0.5- or a 1-pounder made in Great Britain. These three cannon and one swivel are dated to the late-eighteenth century.

Swivel Gun

Most of the cannon in the collection are of the merchant style and are shorter and lighter than their governmental counterparts. Merchants and American military importers of the period preferred smaller cannon because they entailed lower manufacturing, operating, and shipping costs. It is hoped that further analysis will reveal additional information about these and the remaining cannon to be conserved. The CRL’s conservation and research efforts will preserve and contribute to the significant history of the Alamo event and its context in the Texas Revolution.

Once the remaining cannon are conserved, their preliminary identifications and photographs will be uploaded to this page.

The Historical Background

            In the mid-eighteenth century, a Spanish mission was built on the San Antonio River. At that time, the mission's founders and the first Spanish soldiers garrisoned there did not realize the significance that "El Alamo" would play nearly a century later. Many tumultuous events led to the final siege of the Alamo—events that have intrigued subsequent generations and been the source of much scholarship and legends.

            The hinterlands between the United States and Mexico were a source of continued rebellions and revolts throughout the eighteenth and nineteenth centuries. The American immigrants who populated this borderland largely preferred the federalist government of the United States over Mexico's increasing centralism and were troubled over the loss of Texas's independence after the Mexican Constitution in 1824. These American immigrants, along with other Mexican federalists, incited a revolt. This uprising began in October 1835 and would last less than a year, but the outcome would change the political, cultural, and geographic landscape of Texas forever.

            One of the most popularly recognized events of the Texas Revolution was the siege of the Alamo. After the Texian and Tejano forces captured the Mexican fortifications in the San Antonio region in early December 1835 (including the Alamo garrison), General Santa Anna gathered an army and marched it toward Texas in retaliation. Sam Houston, a Major General of the Texian Army, issued an order to Colonel Jim Bowie to destroy the Alamo fortifications, recover 24 cannons from the site, and bring them back to an eastern Texian fortification. Bowie knew that moving 24 cannons without oxen or mules would be nearly impossible,  deciding that it would be best to keep the cannons in place, reinforce the Alamo, and wait for Colonel William Travis to arrive with additional troops to garrison the fortifications in San Antonio.

            When Santa Anna and his army of around 8,000 men made their way north, they easily retook San Antonio and set their sights on the small Alamo fortification garrisoned by no more than 200 Texians and Tejanos. Santa Anna's army laid siege to the fortifications for two weeks, and on March 6, 1836, Santa Anna's army charged. After only 90 minutes, the fighting was over. All of the Texian and Tejano soldiers were killed, but Santa Anna lost over 1,500 men and more than 500 others were wounded.

            Santa Anna wanted to ensure that news of his victory spread across the territory and would serve as an example to other rebellious Texians and Tejanos. To that effect, Santa Anna fouled the artillery and destroyed some of the fortifications so that they could not be used in any further engagements. Although Santa Anna could render the Alamo fortifications and cannons inoperable, he could not control how other Texians and Tejanos responded to the event. For the remainder of the Texas Revolution, the Texian Army invoked the memory of the Alamo siege and battle to inspire soldiers to join the cause and to harden their resolve. The Texas Revolution ended in April 1836 when the Mexican Army was ordered to retreat upon Santa Anna’s capture at the Battle of San Jacinto.

            After Texas was annexed, the United States used the Alamo site as a military complex until 1876. Later in 1905, the Daughters of the Republic of Texas purchased and began to restore the mission and surrounding buildings. In 2015, control over the Alamo was given to the Texas General Land Office, and the site was designated as a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage site. Today, the site is open to the public and serves as a platform to learn about the Alamo story and other early Texas history.

Contract Services

The CRL works with a variety of academic institutions, museums, historical societies, government offices, and private individuals. Our goal is to create viable conservation strategies of the highest standard that can be accomplished at minimal cost. For more information, visit our services page.


Read about the faculty and conservators who run the Conservation Research Labratory. We are also aided by several individuals who volunteer their time to help conserve artifacts. If you are interested in joining the volunteers at the CRL, please contact our lab manager.



Monetary donations and volunteer workers are vital to the ongoing success of the Conservation Research Laboratory. If you would like to volunteer your time and expertise, please write us here. If you would like to become one of our donors, please click the link below and direct your gift to: Center for Maritime Archaeology and Conservation.