Tomás Mejía

Early military career

Mejía enlisted in the army at Jalpan when government forces under Juan Cano arrived there. Cano was impressed by the prefect's son and his talent for horse riding, so he wrote a letter of recommendation to President Anastasio Bustamante to get Mejía admitted to the Military Academy in Mexico City. Mejía's first tour of service was in the Apache–Mexico Wars, where he was stationed in Chihuahua and fought the Apache from 1842 to 1845, earning promotions.

After the U.S. annexed Texas, Mejía joined the Army of the North patrolling the frontier and was transferred to Monterrey. He saw action at the Battle of Buena Vista as the Mexican army fell back. After that battle, the bulk of the Mexican army was recalled to the capital, and Mejía stayed in the north as part of a garrison at San Luis Potosí until the war ended. In 1849 he was granted the rank of commander.

In 1850, during Mariano Arista's presidency, a revolt led by Quiros broke out in the Sierra Gorda; Mejía was among the troops sent to pacify the region. The operation succeeded and Quiros was executed at the end of the year. Mejía was made military commander of the region, and when the Arista administration was overthrown in 1853, he kept his post as the region's political administrator. During the Plan of Ayutla revolt against Santa Anna in 1854, Mejía remained loyal to the government and crushed a local revolt.

After the governor of Querétaro was overthrown, Mejía tried to join a counter-revolt that surrendered; he was pardoned by the new liberal government.

Reform War

Mejía fought on the conservative side during the civil war that followed President Comonfort's backing of Zuloaga's Plan of Ayutla. He joined President Miramón to occupy San Luis Potosí on 13 September 1858 and defeated the liberal general Santiago Vidaurri on 29 September. In April 1859, Mejía was among the conservative troops falling back upon Mexico City, where they routed liberal troops under Santos Degollado. On 12 April, Mejía participated in a Mexico City celebration of that victory.

On 19 April, Mejía and Márquez were dispatched with a strong army to operate in Michoacán. The war turned against the conservatives in 1860. Miramón failed to capture the liberal capital of Veracruz, and another attempt in July failed due to U.S. Navy intervention. Mejía was present at the Battle of Silao on 10 August, where the conservatives were routed.

Miramón retreated to Mexico City, which the liberals finally captured in January 1861. When the conservative government fell, Mejía was at Querétaro and escaped afterward to the Sierra Gorda.

Second French Intervention

After the conservative government fell, Mejía continued the revolt from Jalpan. He captured Rio Verde and took the garrison commander Mariano Escobedo prisoner. False stories circulated that Escobedo had been shot, but Mejía actually let him go. Escobedo would later capture Mejía during the Siege of Querétaro.

After taking Rio Verde's war supplies, Mejía returned to Jalpan and joined forces with Leonardo Márquez and Ramón Méndez to form an army of about two thousand. Márquez reprimanded Mejía for not shooting Escobedo, warning that Escobedo would one day have him shot. The government sent Manuel Doblado to Jalpan, but Mejía defeated him in multiple skirmishes before routing him at Cuesta del Huizache, forcing Doblado to retreat from the Sierra Gorda. In May, Mejía briefly occupied Querétaro, and around that time President Benito Juárez placed a bounty of 10,000 pesos on Mejía's head.

Mejía left Querétaro and the Sierra Gorda, heading to Hidalgo, where on 5 July he attacked Huichapan and took all its garrison prisoner. He then fell back to the Sierra Gorda to join the rest of the conservative forces.

Second Mexican Empire

Marshal Forey gave him a warm welcome and restocked his supplies. Mejía then took charge of military operations across the interior. He was there when the Assembly of Notables opened in July, the group that decided to set up a monarchy and ask Maximilian of Habsburg to take the throne. On Christmas Day, Mejía seized San Luis Potosí.

Two days later, liberal forces under Miguel Negrete tried to reclaim the city but were crushed, losing all their equipment and leaving nine hundred prisoners. That defeat also made liberal generals Aramberri, Parrodi, and Ampudia give themselves up. In May, Manuel Doblado led a liberal attack on the town but suffered a heavy loss, which drove Doblado out of the country. For this win, Napoleon III gave Mejía the cross of the Legion of Honour.

On 12 June, Mejía stood in the National Palace for the official welcome of the royal couple. The Knights of Guadalupe picked him as their spokesman, and Emperor Maximilian hugged him.

Republican General Negrete, along with some American mercenaries, took over towns along the Río Grande, so Mejía pulled back to Matamoros to wait for help. He complained to the American commandant at Clarksville that the U.S. was aiding the Republicans, but the commandant said those men acted on their own. Still, another American raid led Washington to remove that commandant and scold the soldiers involved.