1824 Alamo Flag History
The Alamo flag was created by replacing the Eagle in the center of the Mexican tricolor with the year "1824", referencing the 1824 Constitution of Mexico, in support of which Texas was fighting. This was the first flag approved for use by rebel forces by a Texan legislative body. In 1835, the Texan provisional government approved the use of this flag for privateers preying on Mexican commerce.
It is clear by their writings that the men who stayed in Bexar to defend the Alamo wanted no part in restoring the Mexican Constitution. From the very start, they had joined the volunteer army to fight for Texas Independence and they were frustrated with the provisional government of Texas for its temerity in declaring it.
Unlikely 1824 Alamo Flag actually used at Alamo Battle
It has often been reported that the 1824 Alamo flag was flown by Texan forces at the Battle of the Alamo. However, this had never been alleged until 1860, long after the battle. Modern writers have pointed out that the use of the 1824 flag at the time and place of the battle is highly unlikely. It is likely that the actual "Alamo flag" referred to by accounts of the time was the Lone Star and Stripes, which had been depicted in use at earlier battles such as Goliad, and was widely referred to as the "Texian flag".