Depends on what San Jacinto you are talking about.A battle? A monument? A county? A holiday? All of the above? None of the above?
San Jacinto was the decisive battle of the Texas Revolution that won Texas its independence from Mexico (fought Apr. 21, 1836). Therefore it is a very popular name in Texas. As such, it is all of the above in Texas. The battle was just explained, the holiday is April 21, the monument is outside of Houston, and the county is also near Houston, (county seat Coldspring).