The Battle of the Alamo was a conflict that took place in North America on Earth in 1836. The battle was fought at the Alamo mission by inhabitants of what would become the American state of Texas against Antonio López de Santa Anna of Mexico. Among the prominent Texans who stood against Santa Anna were Jim Bowie, William B. Travis, and Davy Crockett.
In 2374, Miles O'Brien first thought of the idea of creating a holosuite program of the Battle of the Alamo, although Julian Bashir was not keen on using a program in which they would lose. (DS9 episode: "Wrongs Darker Than Death or Night")
In one of their uses of the holosuite program, O'Brien and Bashir managed to make the Mexican Army retreat, although Santa Anna later attacked San Jacinto and defeated Sam Houston, bringing the war to an end with Mexico as the victor. Santa Anna's troops later returned to the Alamo to attack it again. It was at this point that O'Brien and Bashir ended the program. (DS9 short story: "The Best Defense...")
O'Brien later built a model of the Alamo to see if he and Bashir could find a way to actually win the battle against Santa Anna. Bashir suggested that, by strengthening the walls, adding more cannons or building a moat, they might win, although O'Brien pointed out that if Bashir really wanted to win, he should play Santa Anna. (DS9 episode: "The Changing Face of Evil")
After O'Brien left Deep Space 9 at the end of the Dominion War, Ezri Dax asked Bashir if he wanted to use the Battle of the Alamo program, although Bashir was not keen to do so without O'Brien. (DS9 episode: "What You Leave Behind")