A month later, the laughter finally died down in Spain and they realized that, holy shit, this Long guy is actually serious. So they sent a 500-strong force to drive him and his followers the hell out of Texas.
Long escaped with his life and whatever dignity he imagined he still had -- and immediately proceeded to raise another army, this time against the freshly independent Mexico that was now in possession of his precious Texas. He managed to gather some 300 men (and his pregnant wife, because whatever could go wrong?), march in Texas yet again and straight up commandeer a Mexican military fort.
Noted for its excellent pre-natal plan.
Mexico, like Spain before, was getting a bit annoyed by now, so they went in and arrested Long. He was sent to a prison in Mexico City where he was assassinated by a sentry in 1822, presumably while trying to recruit him into his Texas Crusade Mk. III.