Answer:
the Battle of San Jacinto
Step-by-step explanation:
Beginning in 1824, Mexico was a democratic republic with a constitution. But, within a decade, it was taken over by an absolute dictator, Santa Anna, who got rid of the constitution. This made many Mexican citizens very unhappy, especially those in some of the Mexican states, who felt that their ability to participate in the government had been taken from them. This was especially true in Coahuila and Texas.
During the late 1820s and early 1830s, Anglo settlers in Texas had been happy to swear allegiance to Mexico and its Constitution of 1824, becoming Mexican citizens. But, when the dictator Santa Anna seized control of the government, tensions began to rise. So, in September 1835, the dictator Santa Anna sent his brother-in-law, General Cos, with a force of 500 soldiers to the state of Texas to quiet any disturbances that might arise among the local population.
Alarmed at this, Stephen F. Austin, one of the most influential Texians, called on local municipalities to raise militias to defend themselves. In a number of minor incidents, disagreements between Texians and officers of the dictator’s army led to some minor skirmishes in Texas. In October, a detachment of 100 government dragoons attempted to seize cannon in the possession of the local militia at Gonzales. Warned of the detachments intentions, the Gonzales militia raised a flag with the words “Come and Take It,” and then fired the cannon at the government detachment.
As word of the arrival of government forces spread throughout Texas, farmers, ranchers and townsmen took up arms and headed west for the old village of San Antonio de Bexar, where General Cos and his 500 troops joined another force of 150 government troops, and barricaded themselves in the town. In mid-October, the civilian volunteers besieged the dictator’s army which had barricaded itself in the town of Bexar. On November 18, a force of volunteers from New Orleans arrived and joined the Texian forces. On December 5, the Texians attacked the dictator’s forces at Bexar. The fighting continued for several days, until December 10, when General Cos surrendered and agreed to take his government troops out of Texas.
After the departure of Cos, the Texians occupied and fortified the nearby abandoned mission San Antonio de Valero. The mission was known to history as “The Alamo,” because of its cottonwood trees. On February 23, 1836, General Santa Anna led 1,500 troops into San Antonio and surrounded the Alamo and its 188 defenders. On March 2nd, 1836, while the Alamo defenders were under siege, a convention at the town of Washington signed the Texas Declaration of Independence.
At that point in time, Mexico lost Texas. The brutal martyrdom of the Texian defenders of Goliad and the Alamo, made it certain that Texians would never again agree to live under Mexican rule. On April 21, 1836, the Texian army under Sam Houston soundly defeated the dictator Santa Anna’s army at the Battle of San Jacinto, and the independence of Texas was completed.
That is how Mexico “lost” Texas. It was the natural result of a number of very bad decisions made by the dictator Santa Anna, who was an egotistical and dictatorial madman. He miscalculated, and thought he could mistreat the Texians in the same way that he mistreated Spanish-speaking Mexicans. While Spanish-speaking Mexicans were meek and acquiescent to the dictator, the Texians would have none of it.