Several days later, on December 1, a handful of Americans in Béxar convinced Cos to allow them free passage from the city. Although they had promised to leave the country, the men, including Samuel Maverick,[14] instead joined the Texian Army and provided information about the Mexican defenses and the low morale within the town. Buoyed by their Grass Fight victory, on December 5 the Texians launched an attack on Béxar;[15] Cos surrendered on December 9.[16] As a condition of their parole, the Mexican troops were forced to leave the province, leaving the Texas colonists in full control.[17]