Mexican president Guadalupe Victoria refused. Two years later, Andrew Jackson increased the United States' offer to $5 million; President Vicente Guerrero again declined to sell. In July 1829, Mexican authorities had other concerns, as General Isidro Barradas landed 2,700 Spanish troops to the eastern coast of Mexico, near Tampico in an attempt to reclaim the country for Spain. At the request of the government, Austin mustered a local militia to help defend Texas if the invasion were to reach the northern regions of the country. Yucatan governor Antonio López de Santa Anna led a force of Mexican troops to halt the invasion. Barradas surrendered as his troops suffered greatly from tropical diseases, and Santa Anna was hailed as a hero. During the invasion, the Mexican Congress had granted war powers to President Guerrero, making him essentially a monarch. This alarmed the Anglo colonists in Texas, who were accustomed to a separation of powers. Precursor to revolt Mier y Teran's 1828 report had recommended new garrisons in Texas which could oversee the Anglo colonists and encourage Mexicans to resettle in the area. The new garrisons were to be partly staffed by convicts. The first was established along Galveston Bay in 1831 at the site of present-day Anahuac. It became the first port in Texas to collect customs. A second custom port, Velasco, was established at the mouth of the Brazos River, while a third garrison established Fort Teran on the Neches River below Nacogdoches to combat smuggling and illegal immigration. Mier y Teran further ordered the garrison at Bexar to abandon their fort and create a new presidio. Fort Tenoxtitlán was established in 1830 on the west bank of the Brazos River, above San Felipe. Shortly after the fort was completed, 50 immigrants from Tennessee arrived in the area under empresario Sterling C. Robertson. The settlers had arrived illegally, as Robertson's contract had been invalidated by Guerrero's 1830 laws. The garrison commander chose not to expel them, instead sending to Mexico for advice. Three months later he received instructions to expel the settlers immediately. He chose not to do so, allowing the Robertson's Colony to be saved. The fort closed in 1832. After having received no replacements or supplies, the commander finally ordered all of the soldiers to return to San Antonio. Anahuac was placed under the control of Colonel Juan Davis Bradburn. Bradburn enforced the 1830 laws strictly, angering many