With Lafitte's lack of assistance, the expedition soon ran low on provisions. Long dispersed his men to forage for food. Discipline began to break down, and many men, including Bowie, returned home. In early October, Lafitte reached an agreement with Long to make Galveston an official port for the new country and name Lafitte governor. Within weeks, 500 Spanish troops arrived in Texas and marched on Nacogdoches. Long and his men withdrew. Over 40 men were captured. Long escaped to Natchitoches, Louisiana. Others fled to Galveston and settled along Bolivar Peninsula. Undeterred in his defeat, Dr. Long returned once more in 1820, Long joined the refugees at Bolivar Peninsula on April 6, 1820, with more reinforcements. He continued to raise money to equip a second expedition. Fifty men attempted to join him from the United States, but they were arrested by American authorities as they tried to cross into Texas. The men who had joined Long were disappointed they were paid in scrip, and they gradually began to desert. By December 1820, Long commanded only 50 men. With the aid of Ben Milam and others, Long revitalized the Supreme Council. He later broke with Milam, and the expedition led an uncertain existence until September 19, 1821, when Long and 52 men marched inland to capture Presidio La Bahía. The town fell easily on October 4, but four days later Long was forced to surrender by Spanish troops. He was taken prisoner and sent to Mexico City, where about six months later he was shot and killed by a guard – reportedly bribed to do so by José Félix Trespalacios, thus ending the Long Expeditions. Along with the rest of Mexico, Texas gained its independence from Spain in 1821 following the Treaty of Córdoba, and the new Mexican state was organized under the Plan of Iguala, which created Mexico as a constitutional monarchy under its first Emperor Agustín de Iturbide. During the transition from a Spanish territory to a part of the independent country of Mexico, Stephen F. Austin led a group of American settlers known as the Old Three Hundred, who negotiated the right to settle in Texas with the Spanish Royal governor of the territory. Since Mexican independence had been ratified by Spain shortly thereafter, Austin later traveled to Mexico City to secure the support of the new country for his right to settle. The establishment of Mexican Texas coincided with the Austin-led settlement, leading to animosity between Mexican authorities and ongoing American settlement of Texas.