Siege of The Alamo - Background

Background

In 1835, as the Mexican government began to shift away from a federalist model, violence erupted in several Mexican states, including the border region Mexican Texas. By the end of the year, Texian forces had expelled all Mexican soldiers from the area. In Mexico City, President Antonio López de Santa Anna had begun gathering an army to retake Texas.

When Mexican troops departed San Antonio de Béxar (now San Antonio, Texas, USA), Texian soldiers established a garrison at the Alamo Mission, a former Spanish religious outpost which had been converted to a makeshift fort. Described by Santa Anna as an "irregular fortification hardly worthy of the name", the Alamo had been designed to withstand an attack by native tribes, not an artillery-equipped army. The complex sprawled across 3 acres (1.2 ha), providing almost 1,320 feet (400 m) of perimeter to defend. An interior plaza was bordered on the east by the chapel and to the south by a one-story building known as the Low Barracks. A wooden palisade stretched between these two buildings. The two-story Long Barracks extended north from the chapel. At the northern corner of the east wall stood a cattle pen and horse corral. The walls surrounding the complex were at least 2.75 feet (0.84 m) thick and ranged from 9–12 ft (2.7–3.7 m) high.

On February 11, the commander of the Alamo, Colonel James C. Neill, left the Alamo, likely to recruit additional reinforcements and gather supplies. In his absence, the garrison was jointly commanded by newcomers William B. Travis—a regular army officer— and James Bowie, who had commanded a volunteer company. As the Texians struggled to find men and supplies, Santa Anna's army began marching north. On February 12 they crossed the Rio Grande.

On February 16 and February 18 local resident Ambrosio Rodriguez warned his good friend William Barret Travis that their relatives further south claimed that Santa Anna was on the march towards Bexar. Two days later Juan Seguin's scout Blas María Herrera reported that the vanguard of the Mexican army had crossed the Rio Grande. There had been many rumors of Santa Anna's imminent arrival, but Travis ignored them. For several hours that night a council of war held at the Alamo argued over whether to believe the rumors. Travis was convinced that the Mexican army would not arrive in Bexar until at least mid-March. He, and others in the Texian army thought Santa Anna would not march until spring, when the grass had begun to grow again. They overlooked the fact that mesquite grass sprouted earlier than normal grass. Travis had also assumed that Santa Anna would not have begun gathering troops for an invasion of Texas until after he had learned of Cos's defeat; the Texians did not realize that Santa Anna had begun preparations for an invasion months before.

Despite the Texian disbelief, by the evening of February 20 many of the residents of Bexar began to pack their belongings in preparation for leaving. The next day, fifteen of the Tejano volunteers at the Alamo resigned. Seguin had asked Travis to release the men so that they could help evacuate their families, who were in the path Santa Anna would take to reach Bexar. Santa Anna had crossed the Rio Grande on February 16. The next night, his army camped on the Nueces River, 119 miles (192 km) from Bexar. Texians had previously burned the bridge over the Nueces, forcing the Mexicans to build a makeshift structure of branches and dirt in the pouring rain. The delay was brief, and on February 19 the vanguard of the army camped along the Frio River, 68 miles (109 km) from Bexar. The following day they reached Hondo, less than 50 miles (80 km) away. By 1:45 pm on February 21 Santa Anna and his vanguard had reached the banks of the Medina River, 25 miles (40 km) from Bexar. Waiting there were dragoons under Colonel Ramirez y Sesma, who had arrived the previous evening. With no idea that the Mexican army was so close, all but 10 members of the Alamo garrison joined about 2000 Bexar residents at a fiesta to celebrate George Washington's birthday. Centralists in Bexar soon alerted Santa Anna to the party, and he ordered General Ramirez y Sesma to lead a cavalry force to take the Alamo while the garrison celebrated elsewhere. The raid had to be called off when sudden rains made the Medina unfordable. The next night, Santa Anna and his army camped at Leon Creek, 8 miles (13 km) west of what is now Downtown San Antonio.