Created in 1835, the "1824 Flag" was the first approved for use by rebel forces by a Texan legislative body.  It was derived from the Mexican flag, with the date 1824 replacing the eagle.  This was a reference to the Mexican constitution of 1824, in support of which the Texas rebels were fighting.  Despite claims that it flew over the Battle of the Alamo, historians believe that it was highly unlikely.
Own work
Glasshouse