On October 2, 1835, about 100 Mexican dragoons under Lieutenant Francisco Castaneda rode up to the Guadalupe crossing at Gonzales and were met by roughly 140 Texian militia who told them to go back. Shots were exchanged. Nobody died. One Mexican soldier was knocked off his horse, and the column withdrew to San Antonio de Bexar, which is where the serious fighting would happen later in the year.
It was about a cannon. The Mexican authorities had lent the settlers a small bronze gun in 1831, when the district was exposed to Comanche raids, and asked for it back in September 1835 as the government under Santa Anna tightened its control over the states. The settlers refused, and Gonzales became the test of how far they would go.
Santa Anna had spent two years dismantling the federal system. The constitution of 1824 was set aside in 1834, the state legislatures were dissolved, and troops were sent into the states that objected. Coahuila y Texas was one of them. The settlers in Texas had mostly come from the United States under empresario contracts granted since 1821, and they numbered about 30,000 against perhaps 5,000 Tejanos.
The flag the militia carried, with a cannon on it above the words Come and Take It, was made for the day, and it is the most reproduced object of the revolution. The skirmish is remembered as a battle because it was first. Within weeks the Texians had taken Goliad and San Antonio, and by the end of the year the Mexican army had been pushed back across the Rio Grande.
That is when the war turned serious. Santa Anna crossed the river in February 1836 with about 6,000 men, took the Alamo on March 6 and executed the garrison at Goliad at the end of the month. Sam Houston's army destroyed a Mexican force at San Jacinto on April 21 and captured Santa Anna the next day. Texas was independent until it joined the United States in 1845, which started a war with Mexico a year later.