The Siege of the Alamo (23 February to 6 March 1836) was an engagement of Texian forces with the Mexican Army, leading up to the Battle of the Alamo on the morning of 6 March 1836. The 13-day siege and battle has become legendary and is among the most famous military conflicts in history.

The Battle of the Alamo is regarded as one of history's greatest last stands, as between 185 to 250 defenders, after enduring constant bombardment for twelve days, repelled two assaults by the Mexican Army, numbering over 2000, under President and General Antonio López de Santa Anna (1794 to 1876), on the morning of 6 March. A third assault took the fort and, under Santa Anna's orders, no prisoners were taken. Those who survived the battle were executed shortly afterwards.

The Texas Revolution began with the Battle of Gonzales on 2 October 1835. The Texians won every engagement for the rest of 1835, culminating in the Siege of Béxar (modern-day San Antonio) in which they defeated troops under General Martín Perfecto de Cos (1800 to 1854), who had held the Alamo. The Mexican garrison was the last in Texas, and when Cos surrendered, it meant the end of Mexican military strength in the region.

The Texians then took the Alamo, and Colonel James C. Neill (circa 1788 to 1848), with a garrison of 100 men, set about repairing damage done to the walls and buildings during the siege. Neill believed the Mexican Army would return – and so did General Sam Houston (1793 to 1863). When Cos surrendered, he had left behind 19 cannons, small arms, powder, and ammunition. Houston sent Colonel James 'Jim' Bowie (1796 to 1836) to the Alamo with orders to remove the artillery and anything else of use and then blow it up to keep it from being refortified by Santa Anna.

Bowie and Neill both felt the Alamo should be held as it would serve as a first line of defense should Santa Anna decide to retake Texas. Bowie appealed to the newly elected governor of Texas, Henry Smith, who approved the plan, and men began to arrive at the Alamo to reinforce the commands of Bowie and Neill. Among these were Juan Seguín (1806 to 1890), leading a unit of Tejanos, Lt. Colonel William Barret Travis (1809 to 1836), and the legendary frontiersman and former congressman, David 'Davy' Crockett (1786 to 1836) of Tennessee, leading more volunteers.

On 11 February, Neill left to tend to personal business, and Travis took over his command. Some of the men objected to being led by a regular army officer, however, and, after some difficulties between the two men and their followers, Bowie and Travis agreed to co-command the garrison.

The Alamo had been established as a mission in 1718 and, by 1758, had expanded into a complex of 3 acres (1.2 ha). The walls enclosing the buildings and courtyard had been built to deter attacks by Apache and Comanche raiding parties and were already in disrepair when Cos fortified it in 1835. Travis and Bowie had the men strengthen the walls, which were 9 to 12 feet high (2.7 to 3.7 m) and 2.75 feet (84 cm) thick. Engineer Green B. Jameson oversaw the work, installed ports for small arms, and built catwalks along the interior of the walls to allow men to stand and shoot.

Travis sent out letters calling for reinforcements, especially to Colonel James W. Fannin (1804 to 1836) at Fort Defiance in Goliad, who had 350 to 400 men under his command. Travis was sure that Santa Anna, if he did come, would not start for Texas until mid-to-late March and, by that time, the walls of the Alamo would be ready to hold against attack, and he would have a garrison large enough to defend them properly.

Between 14 and 18 February, reports arrived in Béxar that Santa Anna had crossed the Rio Grande, the border between Texas and Mexico, on the 12th. Travis dismissed these as rumors and gossip. On 20 February, Juan Seguín received a report that General Joaquín Ramírez y Sesma, leading 1500 men, was marching toward the Alamo. Travis called a war council, but the report was ultimately dismissed as another rumor.

On 22 February, having received no further reports – and confident that Santa Anna's army had not yet begun their march – Travis and Bowie allowed the garrison to go into town and celebrate the birthday of George Washington. At this point, Santa Anna was only 25 miles (40 km) away from Béxar. Hearing that the garrison had left the fort, Santa Anna ordered Sesma to march on Béxar immediately, but a heavy rainstorm that night, swelling creeks and streams, made this impossible.

23 to 24 February

On the morning of the 23rd, with many of the garrison heavily hungover from the night before, Travis noticed commotion in the town and, when he asked what was happening, was told the people were leaving before Santa Anna arrived, which would be soon. One of the townspeople told Travis that General Sesma was only a few miles from Béxar and approaching quickly. Travis was not convinced but still posted one of his men in the bell tower of the San Fernando Cathedral to keep watch.

Around 3:00 p.m., the bell began ringing, and Travis ran up to the belfry along with Dr. Sutherland, John "El Colorado" Smith, and others, but they could see nothing. The sentry claimed he had just seen the army, and so Sutherland and Smith were sent out to check. They returned quickly to report a large Mexican force 1.5 miles (2.4 km) away. Travis ordered everyone into the Alamo. Some men had their families with them in Béxar – such as Captain Almaron Dickinson (1800 to 1836), who had arrived with his wife, Susanna (circa 1814 to 1883), and their infant daughter Angelina – and these joined the men in taking refuge inside the Alamo complex.

From the walls of the Alamo, Travis saw Santa Anna and his army enter Béxar. A red flag was raised from the San Fernando Cathedral belfry, signaling no quarter for the garrison, and Travis answered this with a shot from the 18-pounder cannon. The Mexicans returned fire from four cannons. Bowie heard someone say there was a bugle call from the Mexicans, which may have been a request to parley. He quickly wrote a note and sent Green B. Jameson with it toward the Mexican side. Jameson returned with the news that there would be no terms – the garrison would need to surrender unconditionally. Travis, annoyed by Bowie acting without first consulting him, then sent his own man, Albert Martin, who came back with the same news. Travis and Bowie then agreed to fire the 18-pounder again.

The next morning, Santa Anna ordered the bombardment of the Alamo by his 8-pound cannons. This would continue the rest of the day. Inside the fort, Bowie fell ill with a fever, chills, and a temperature of between 101 and 104 °F (38 to 40 °C). He retired to the room of his late wife's cousins – Juana Navarro Alsbury and her sister, Gertrudis Navarro – who had also taken refuge in the Alamo, and they became his nurses.

The most famous event of 24 February at the Alamo was Travis' letter, "To the People of Texas & All Americans in the World," which reads:

I am besieged, by a thousand or more of the Mexicans under Santa Anna – I have sustained a continual Bombardment & cannonade for 24 hours & have not lost a man. The enemy has demanded a surrender at discretion, otherwise the garrison are to be put to the sword, if the fort is taken. I have answered the demand with cannon shot & our flag still waves proudly from the walls. I shall never surrender or retreat. Then, I call on you in the name of liberty, of patriotism, & everything dear to the American character, to come to our aid, with all dispatch. The enemy is receiving reinforcements daily & will no doubt increase to three or four thousand in four or five days. If this call is neglected, I am determined to sustain myself as long as possible & die like a soldier who never forgets what is due to his own honor & that of his country – Victory or Death.

(Davis, 541)

Travis, now sole commander, sent the letter out with Albert Martin and then returned to the wall. The Mexicans continued their bombardment of the Alamo into the evening, but the cannons lacked power at that range to do any damage. Most cannonballs fell harmlessly into the courtyard, and the defenders would fire them back. Santa Anna also ordered his military band to play the deguello – the "slit throat" song signaling no quarter – through the night while his men moved some of the cannon closer to the Alamo.

25 to 29 February

The next morning, the Mexican artillery began shelling early to cover the approach of about 200 infantry who positioned themselves within 100 yards (91 m) of the Alamo behind some huts. Travis ordered his men to fire and trained his cannons on the huts. The Mexicans retreated, and Travis called for volunteers to go out and burn the huts. He then wrote a letter to General Sam Houston appealing for reinforcements. When he asked for a volunteer to take it out, no one stepped forward. The men elected Juan Seguín to go, which Travis objected to because he felt Seguín was too important, but the vote held, and Seguín left with the letter.

Meanwhile, at Goliad, Colonel Fannin left Fort Defiance on either the 25th or 26th en route to the Alamo. He had not gone more than a mile when one of the wagons broke down, and, while that was being repaired, two others failed. Fannin ordered his men to camp for the night, and the next morning they found the oxen needed to pull the wagons and cannon had wandered off. They also realized no one had thought to carry provisions, and they had little food or ammunition. Fannin then ordered his company to turn around and return to Fort Defiance.

Between the 25th and 29th, the Mexican artillery kept up their bombardment, but the cannons were still too far out of range to pose any real threat. By 29 February, Houston had received Travis' letter but dismissed it as "a damned lie" (Davis, 547), claiming there could not be such a large Mexican force at Béxar because Santa Anna would not have marched north in winter. He claimed Travis was exaggerating the danger of his position to draw attention to himself in hopes of replacing Houston as general of the army. At Washington-on-the-Brazos, where the provisional government was meeting, he convinced many who were preparing to go to the Alamo's aid that it was all a hoax Travis had dreamed up, and so no help was sent. On 2 March, the delegates gathered there declared Texas an independent republic.

1 to 3 March

In Gonzales, however, a group of volunteers had rallied, and on 1 March, 32 arrived at the Alamo, slipping through the Mexican lines. This brought the number of Alamo defenders up to around 200 men (possibly 250). Santa Anna had offered amnesty to any Tejano who left the fort, and many who had been in Seguín's company requested leave, which was granted by Bowie, who, by this time, had been moved to a room in the low barracks.

On 3 March, Santa Anna was reinforced by at least 1000 more troops, and the defenders in the Alamo watched as there was a great celebration in town. The troops were not only responding to the reinforcements but to the news that General José de Urrea had defeated the Texian force at the Battle of San Patricio on 27 February.

Also on the 3rd, James Butler Bonham (1807 to 1836), who had been sent out by Travis for reinforcements, rode through the Mexican lines to deliver the news that help was coming. He told Travis that 60 men had rallied at San Felipe and that Fannin had left Fort Defiance with 320 men on 28 February. Further, he had been told that 300 more Texians were due to arrive in San Felipe and would be sent on to the Alamo. This would bring the garrison strength up to over 800 men, and Travis knew he would now be able to properly man the Alamo's walls. Still, as he had not had word from Fannin himself, Travis seems to have doubted Bonham's report, as he stated in a letter he sent out that same day, again appealing for reinforcements, gunpowder, and ammunition. None of these promised troops would arrive.

4 to 6 March

The Mexican artillery continued to bombard the Alamo through the 4th. That afternoon, Santa Anna convened a war council with his senior officers to discuss plans for a full assault on the fort. His officers tried to talk him out of this, noting that two 12-pounder cannons were due to arrive within the next few days, and with these, they could easily reduce the walls of the Alamo and force a surrender without losing a man.

Santa Anna rejected this proposal. General Cos, who had been defeated at the Alamo in December 1835, was his brother-in-law, and his family's honor needed to be avenged. A bloodless victory would not accomplish that. Further, according to later reports, Juana Navarro Alsbury left the Alamo the evening of the 4th to tell Santa Anna that the garrison was considering surrender or whole-scale desertion of the fort if reinforcements did not arrive soon. Santa Anna then prepared for an early morning attack on the Alamo, which would commence on the 6th. Scholar William C. Davis notes:

Santa Anna stayed because he wanted to, taking his time to set up an inevitable and total victory. An army the size of his could have marched around the Alamo and on to the Texas interior with no fear at leaving two hundred or so Texians in a mud fort in his rear. The Alamo was as much a prison as fort. It kept the Mexicans out, but it kept the Texians in as well, and Santa Anna need only leave behind one of his regiments or a few companies of lancers to contain the garrison, thus eliminating them from any role in the campaign despite being in his rear and on his supply line. In short, so far as the campaign in Texas was concerned, the Alamo and its garrison ceased to really matter by March 1 if not before. From then on it was only important because Santa Anna chose to make it so.

(555)

By 5 March, Santa Anna had surrounded the Alamo and ordered the assault to begin the next morning before dawn. The army was divided into four columns commanded by General Cos, Colonel Francisco Duque, Colonel Juan Morales, and Colonel José María Romero. General Sesma and his lancers would hold positions around the fort to kill any defenders trying to escape or cut down Mexican recruits who retreated without orders. Santa Anna commanded the reserves.

According to a later report, on the evening of 5 March, Travis gathered the men in the courtyard, informed them that he believed an attack was imminent, the Alamo would fall, and they could expect no mercy. He drew a line in the sand with his sabre and asked any man who would stand with him to cross it. The entire garrison crossed the line. Bowie, sick on his cot, is said to have asked some of his men to carry him across. Only one man, Moses Rose, chose to leave, and he would later tell the story to the Zuber family, who published the account in 1873.

Around 10:00 p.m. on the 5th, the Mexican guns stopped for the first time since 24 February, and the Alamo garrison was finally able to sleep through the night. Three guards were posted outside the walls, but they, too, fell asleep, and while all slept, Santa Anna's forces moved into position. The three sentinels were killed in their sleep, and the garrison was unaware they were under attack until, around 5:30 a.m., they heard, "Viva Santa Anna!" and a bugle blast. Travis quickly ran to the north wall with his slave, Joe, and shouted orders to the rest of the garrison. He was among the first to fall, shot in the forehead after firing his shotgun. Joe retreated to his quarters and would later be spared as the Mexicans thought he was a non-combatant.

Two assaults on the Alamo's walls were repulsed, but as they retreated and regrouped, they shifted north until the bulk of the army was at the north wall, which had been weakened by bombardment throughout the siege. The wall was quickly taken, and the Mexican troops swarmed into the Alamo. Jim Bowie was killed in his bed in his room in the low barracks, and the garrison fell back into the long barracks, where the worst of the fighting took place in hand-to-hand combat.

The battle was over in an hour. All the defenders had been killed except for 5 to 7 men who surrendered. According to reports circulating right after the fall of the Alamo and later corroborated by Mexican Colonel José Enrique de la Peña (1807 to 1840), Davy Crockett was among this group. Although General Castrillon interceded on their behalf, Santa Anna ordered the men executed. Mexican losses are estimated at between 400 and 600 killed, with most historians favoring the higher number.

Santa Anna called it "a small affair" though a glorious victory, but his officers disagreed. De la Peña regarded it as a defeat and the battle as completely unnecessary. Santa Anna's victory at the Alamo would be even more costly when Houston rallied his men with the cry "Remember the Alamo!" at the Battle of San Jacinto on 21 April 1836, defeating Santa Anna's army in 18 minutes and securing the independence of Texas.