THE LONE STAR FLAG was officially adopted by the Texas Congress on January 25, 1839, becoming the second national flag of the Republic of Texas. It has been the symbol of Texas ever since. Celebrate our flag by learning more about how it came to be and some of the Revolutionary flags that pre-dated it. Kids (and crafty adults) can try their hand at making a flag, either from history or their own imagination. Free with purchase of ticket to the San Jacinto Museum.