Texas State flag was adopted in 1933. The national flag of the Republic of Texas was the “Lone Star Flag” and it became the state flag when Texas was joined to the Union in 1845. But, Texas had no official state flag from 1879 till 1933 until the Texas Flag code was passed in 1933. The popularity of the state flag and its tri color symbolism has given Texas the nickname of “the Lone Star State”.