There was no company by that name in the 1st Texas or any other regiment of Hood's Texas Brigade, at least not according to H. B. Simpson's brigade history or compendium (he should know). Company I of the 4th Texas was from Corsicana - the "Navarro Rifles". That said, I have also seen this reference (on the Navarro County Texas Gen Web) to the "Corsicana Invincibles" being Company E of the 1st Texas. However, the list of this so-called company contains only 18 names. More likely they were a group of volunteers from Corsicana who enlisted in Company E of the 1st Texas - otherwise known as the "Marshall Guards" from Harrison County.