3rd Regiment of Dragoons was assigned to the expedition to Central Mexico, landing near Vera Cruz with Major General Winfield Scott's army and participating in the Siege of Vera Cruz,
Battle of Churubusco and the Battle of Molino del Rey. The Third Dragoons took part in General Joseph Lane's pursuit of General Santa Anna in January 1848, and Lane's campaign against the guerrilla forces of Joaquín Rea at the action of Atlixco and of Padre Jarauta in late February 1848.