What historic event does the phrase "remember the Alamo" refer to?

The phrase "remember the Alamo" specifically refers to a significant battle during the Texas Revolution. This battle took place at the Alamo Mission in San Antonio in 1836, where a group of Texan defenders, including notable figures such as James Bowie and Davy Crockett, fought against the Mexican army led by General Santa Anna. Despite being outnumbered, the defenders held out for 13 days, which became a symbol of resistance against oppression and a rallying cry for Texan independence. The phrase has since come to embody the spirit of bravery and sacrifice associated with the fight for Texan sovereignty. This context highlights why it is the correct choice in identifying the historical significance of the phrase.