Headquarters, Camp at San Jacinto, Thursday, April 21, 1836:
Dear Fellow Texians,
Our Commander slept unusually late this morning, well after the 6 a.m. sunrise. At about 10 a.m. Mexican General Cos arrived with 400 men. He had left 100 men at the difficult Sims Bayou crossing moving the baggage and ammunition across. The camp was all excited that the Mexicans now had fresh troops which might affect the outcome of the inevitable battle. Houston attempted to down play the event, saying that it was a rouse. Houston claimed that Santa Anna had sent a company out under cover and them marched them into camp with great fanfare to discourage the Texians.
Unbeknownst to the camp, Deaf Smith approached Houston for permission to destroy Vince’s bridge in order to impede any additional re-enforcements. Houston agreed and told him to return quickly. At noon Houston called the first Council of War for the campaign. Houston, Rusk and 8 officers discussed the options. A senior ranking officers were against attacking the Mexicans that day, but rather wait for the Mexicans to attack the Texian’s defendable position. The younger officers want to attack immediately. Houston made no decision and dismissed the meeting at 2 p.m.
Houston felt that a surprise attack in the afternoon might be victorious. It had been observed that Santa Anna had allowed Cos’ men to rest, had permitted the rest of the camp to take lunch and a siesta, had allowed the cavalry to unsaddle their horses to water and feed them and best of all, Santa Anna had failed to post sentries to watch the Texian camp. Houston could form up his army in a low impression in front of his camp without being seen by the Mexican Army. The army could march to within 200 yards of the Mexican breastworks without being spotted. The element of surprise was in his favor.
At 3 p.m. Houston announced that all companies should be assembled for battle. At 3:30 a line, two men deep, spread out 900 yards in the gulley in front of the camp. Houston visited with each company. At 4 p.m. he issued the order to "Trail Arms! Forward!" Sherman was in charge of the second brigade on the left flank. Burleson commanded the first brigade on Sherman’s right. In the center the Twin Sisters advanced with protection provided by Millard’s Regular troops. On the right flank newly promoted Lamar lead the cavalry.
At 4:30 p.m. Sherman’s men invaded the camp of General Cos’ resting troops. Panic quickly developed among the Mexican soldiers and they rushed behind the breastworks for protection. That flood of soldiers disrupted the orderly assembly of the main body of the Mexican Army. About that moment the rest of the Texian Army crested the ridge and began firing randomly which shouting "Remember the Alamo" and "Remember Goliad." To the professional Mexican soldiers it appeared as if they were being attacked by savages. The Twin Sisters began pumping canister shot into the midst of the Mexican camp. The Mexican cannon got off three shots before its crew was killed. Santa Anna emerged from his tent to witness chaos and confusion. He quickly realized the battle was lost and mounted a nearby horse to escape. He knew Filisola had approximately 2,500 troops near Old Fort and Santa Anna took the road back to Filisola by way of Harrisburg. His cavalry followed. Without effective leaders the Mexican infantry broke and ran. The Texians crossed the Mexican breastworks in about 18 minutes as the leaderless infantry scattered.
Although Houston called for his men to stop, the battle had been won, he was generally ignored as the Texian volunteers sought to extract revenge for their fallen comrades at the Alamo and at Goliad. By sunset about 6 p.m. some 600 Mexicans died. Those that surrendered were guarded by officers. Meanwhile Santa Anna’s escape was impeded by the destruction of Vince’s Bridge. Most of the Mexican cavalry had been shot en route to Vince’s and Santa Anna and three others went into hiding among bushes at dusk.
Respectfully yours, An Observer and aide-de-camp
Meanwhile the rest of the Mexican Army: Filisola and the main Mexican Army camped at Thompson’s Ferry with 1,408 men. Urrea with 1,165 men left Mrs. Powell’s home at 4 a.m. and arrived at Columbia at 4 p.m., which was deserted. He then marched to its port (La Puerta) two miles distance.
The Interim Government: Continued conducting business at Galveston. No word has been received about Houston since the 18th.
Route of the Twin Sisters: The injured artillery commander Neill was replaced by Inspector General Lt. Col. George Washington Hockley. The Twins were towed by rawhide ropes by the cannon crew to the rise that separated the two armies. On the command, the Twins opened fire. They were used "with terrible affect" on the Mexican Army.