When Mexican general Ráfael Vásquez briefly occupied San Antonio in March 1842, Green recruited the Travis County Volunteers and stood as their captain; the unit was not involved in combat. In response to this and two other Mexican incursions, Texas launched the punitive Somervell Expedition against Mexico; Green served as its inspector general.
When Mexican general Ráfael Vásquez briefly occupied San Antonio in March 1842, Green formed the Travis County Volunteers and led them as their captain; however, they did not participate in any battles. In response to this and two other Mexican incursions, Texas launched a punitive expedition against Mexico, with Green serving as its chief inspector.