While the crisis along the Mexican-American border worsened, Mexico's Reform War continued unabated. In mid-November substitute President of Mexico, Miguel Miramon, offered to meet with Liberal Generals Degollado, Artega and Doblado. Miramon, having failed at taking Vera Cruz the previous February, was growing fearful that his Conservative base of support was eroding. Miramon's true intentions are not known, but based on surviving letters to Degollado he seems to have hoped to entice them into defecting by offering the three Liberal generals positions within a new moderate-Conservative government.
Regardless of his intentions it came to naught. On November 14, 1859 the discussions broke down and the three Liberal generals left the Calera Hacienda, where the meeting had been taking place. The next day Miramon's 4,000 man army found itself facing a Liberal army over 7,000 strong. The fighting on the 15th proved inconclusive, but Miramon was forced to retreat back into nearby Queretaro. The 16th saw the Liberals establish a siege around the town and Miramon was asked to surrender. Realizing that doing so would almost certainly lead to his execution, Miramon refused all offers for negotiation. The siege continued a for three more days when word came that Leonardo Marquez, a Conservative general and political rival to Miramon, was marching from Guadalajara with 3,000 men to relieve Queretaro. Having already taken heavy casualties Degollado lifted the siege and began to withdraw from Queretaro.
On November 23rd Marquez's column caught up to the Liberal army and attacked while it was in marching formation. Artega escaped, Doblado was injured but also escaped, but Degollado was captured by Marquez. Marquez sent his captive back to Queretaro but refused to subordinate his troops to Miramon. Degollado was executed on November 28th along with seven other Liberal officers. After resting and gathering reinforcements Miramon marched on Guadalajara with the intent of arresting Marquez, but Marquez was not in that city.
Realizing that Miramon, further embarrassed by Marquez's continued successes, now viewed him as an enemy; Marquez chose to march north to San Luis Potosi. His column reached San Luis Potosi on December 8th and spent the next two weeks there gathering supplies and pressing locals into his growing army. Initially, he contemplated confronting Miramon, and on December 25th he departed San Luis Potosi with 6,500 men having the intention of occupying Guadalajara and declaring himself Interim President. But on December 27th, a rider caught up with his column. The man carried a letter from Santiago Vitaurri that described the situation caused by Cortina's raids and in it Vitaurri pleaded for military help.
Although the letter was meant to be read by a Liberal General, Marquez saw an opportunity. A victory of an American invasion would solidify his reputation and propel him into the leadership role of the Conservatives. The stain of Santa Anna would be wiped clean and all of Mexico would rally around him. On December 28th Marquez turned his column north and marched to Ciudad Victoria. He reached the city on January 2, 1860 and declared himself military governor of Tamaulipas. On January 13th he met with Vitaurri in the small town of Montemorelas. Vitaurri agreed to subordinate his militia to Marquez but wished to focus on the capture of Cortina in order to assuage American anger. Marquez had other plans.
Benjamin
NOTES: The battle near Queretaro is where this Reform War begins to really differ from OTL Reform War. In reality Miramon wins the battle without help, but all three Liberal generals escape relatively unharmed. Miramon then marches on Guadalajara and arrests Marquez. Marquez is then sent back to Mexico City as a prisoner. That obviously does not happen here.