As Mora’s dramatic change to Costa Rica’s constitution coincided with the privatization of the country’s commons, its landless peasants were now left helpless.

Mora, along with Bishop Anselmo Llorente, gave a series of speeches to arouse the people and prepare them for the upcoming war.

Mora and his brother placed the emphasis of the Second Campaign on the Costa Rican armed forces cutting off Walker's supply route which used the San Juan River and the steamboats taken by the filibusters from the Accessory Transit Company.

However, Mora met in November 1856 with Silvanius Spencer, Cornelius Vanderbilt's agent, who offered his help on the capture of the San Juan river.

In spite of earning acclaim as a national hero for his efforts in that endeavor, he was overthrown in a coup d'état orchestrated by his opponent Jose Maria Montealegre in August 1859.