<P> 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 . </P> <P> 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 . </P> <P> In the early hours of February 23, residents began fleeing Béxar, fearing the Mexican army's imminent arrival . Although unconvinced by the reports, Travis stationed a soldier in the San Fernando church bell tower--the highest location in town--to watch for signs of an approaching force . Travis then sent Captain Philip Dimitt and Lieutenant Benjamin Noble to scout for the Mexican Army's location . At approximately 2: 30 that afternoon the church bell began to ring; the soldier stationed in the tower claimed to have seen flashes in the distance . Dimitt and Noble had not returned, so Travis sent Dr. James Sutherland and John W. Smith on horseback to scout the area . Smith and Sutherland spotted members of the Mexican cavalry within 1.5 miles (2.4 km) of the town and returned to Béxar at a run . </P> <P> According to later reports from Santa Anna, the cavalry, under General Joaquín Ramírez y Sesma, were supposed to execute a surprise attack on the morning of February 23 . Historian Thomas Ricks Lindley concluded that Sesma's troops had captured a Texian spy, Trinidad Coy, who lied about a Texian ambush further ahead, prompting Sesma to halt at 7 a.m. and wait for reinforcements . Historian Lon Tinkle speculated that the combination of the church bell ringing and the sight of the two Texian scouts led Sesma to believe that the Texians were planning an assault on the cavalry . </P>

Who tried to bring more troops to the alamo but failed