One thing that happened during the Crusaders was a temporary unification of muslim forces under the banner of a famous general called Saladin. He unified muslim forces which were fighting each other (most notably Seljuk Turks with their minor skirmishes before the First Crusade) and managed to create one united muslim force.
The U.S. had Superior Firepower. American cannon crews had roughly double the effective range of their Mexican counterparts and their deadly, accurate fire made the difference in several battles
