Texas Revolution: Battle of the Alamo: After a thirteen-day siege by an army of 3,000 Mexican troops, the 187 Texas volunteers, including frontiersman Davy Crockett and colonel Jim Bowie, defending the Alamo are killed and the fort is captured.

The Texas Revolution was a rebellion of colonists from the United States and Tejanos against the centralist government of Mexico in the Mexican state of Coahuila y Tejas. Although the uprising was part of a larger one, the Mexican Federalist War, that included other provinces opposed to the regime of President Antonio López de Santa Anna, the Mexican government believed the United States had instigated the Texas insurrection with the goal of annexation. The Mexican Congress passed the Tornel Decree, declaring that any foreigners fighting against Mexican troops "will be deemed pirates and dealt with as such, being citizens of no nation presently at war with the Republic and fighting under no recognized flag". Only the province of Texas succeeded in breaking with Mexico, establishing the Republic of Texas. It was eventually annexed by the United States about a decade later.

The Battle of the Alamo was a pivotal event and military engagement in the Texas Revolution. Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna reclaimed the Alamo Mission near San Antonio de Béxar. About one hundred Texians, wanting to defy Mexican law and maintain the institution of chattel slavery in their portion of Coahuila y Tejas by seeking secession from Mexico, were garrisoned at the mission at the time, with around a hundred subsequent reinforcements led by eventual Alamo co-commanders James Bowie and William B. Travis. On February 23, approximately 1,500 Mexicans marched into San Antonio de Béxar as the first step in a campaign to retake Texas. In the early morning hours of March 6, the Mexican Army advanced on the Alamo. After repelling two attacks, the Texians were unable to fend off a third attack. As Mexican soldiers scaled the walls, most of the Texian fighters withdrew into interior buildings. Those who were unable to reach these points were slain by the Mexican cavalry as they attempted to escape. Almost all of the Texian inhabitants were killed.

A siege is a military blockade of a city, or fortress, with the intent of conquering by attrition, or by well-prepared assault. Siege warfare is a form of constant, low-intensity conflict characterized by one party holding a strong, static, defensive position. Consequently, an opportunity for negotiation between combatants is common, as proximity and fluctuating advantage can encourage diplomacy.