By 1865, Spain lost its dominance on the island, leading numerous Dominicans, including Puello, to emigrate to Cuba or Puerto Rico.

In 1840, he achieved the rank of captain, but his military career was cut short after the fall of Boyer in 1843, leading to his retirement along with other officers loyal to the overthrown government.

Appointed first chief of the Second Battalion of the Dominican regiment based in Santo Domingo, he was assigned to the General Staff of Santana, until in 1849, he received the rank of colonel.

Puello asked for a company to garrison San Juan, but his request was denied, causing the revolution to spread to all the towns in the district of Azua.

Despite the difficulties of the battle due to the narrow road and enemy fire from the woods, Puello ordered a vigorous advance and achieved a victory, capturing ammunition, shrapnel, and prisoners of war.

On October 6, the revolutionaries took the city of Baní, and on the next day, San Cristóbal revolted, leaving Azua cut off from the Dominican capital.

Faced with this situation, Felipe Rivero ordered Puello to evacuate Azua, also adding the news of an alleged independence conspiracy in Santo Domingo.

From Baní, he fought approximately 500 Dominican insurgents who were in Alto de la Cruz, causing 50 deaths and some injuries to the rebels through a false retreat, and managing to capture three flags.

In early December 1864, Marshal Puello received confidential information about a possible change of attitude in the inhabitants of the village of Neiba, who were apparently willing to recognize the authority of Spain again.

On December 4, the Spanish expedition was caught in an ambush on the mountain of La Canela, where they faced rebel forces led by José María Cabral.

[5] By late 1864, although the Spanish appeared to be winning the war, a major territorial loss had occurred with the fall of El Seibo.

Furthermore, during the course of the war, the rebels had carried out devastating actions in important cities such as Santiago de los Caballeros and Puerto Plata, burning them down and causing damage valued at some 5,000,000 pesos.

[8] In Santo Domingo, he lost property and family that was left in poverty after having been a prisoner of the enemy, accompanying him to his new destination on the island of Cuba, where he was granted the barracks for the city of Havana.

At that time, some Dominican compatriots who had loyally served the Spanish crown chose to join the ranks of the Cuban Liberation Army, such as Máximo Gómez, Modesto Díaz and Félix Marcano.

However, Puello demonstrated an ardent enthusiasm for defending the Spanish national integrity and assumed command of the troops operating in the jurisdictions of Sancti Spíritus, Morón, Remedios and Ciego de Ávila.

For five months, Puello fulfilled his duty and conscience, traveling more than 300 leagues by day and night, relentlessly pursuing the enemy and sharing the fatigue of war with the soldiers.

War, desolation, fires, hunger and diseases, such as yellow fever and cholera, had turned Puerto Príncipe into a corpse on the verge of the grave.

In addition, he built forts to protect the city from surprises, promoted the repair of the railroad and abundantly supplied the population with food.

However, to his surprise, this confidential news was published in the newspapers, which allowed the rebels to change their plan and build a formidable trench at the Juan Rodríguez Mines, near Guáimaro, on the road to Palo Quemado.

Confident of victory, the insurrection gathered en masse at this strategic point, encouraged by the presence of its self-proclaimed republican government and led by the generals in whom the insurgents had the greatest confidence, such as Ignacio Agramonte and the adventurer Thomas Jordan, an American who had fought in the Confederate Army during the American Civil War and who now held the position of generalissimo of the Cuban Liberation Army.

On January 1, 1870, in the early hours of the morning, the troops under Puello's command found themselves ambushed at the vanguard, receiving a surprise and accurate discharge from the enemy.

The fighting was fierce, with the Cuban rebels defending the bastion of independence with double or triple the strength and precision weapons, while the Spanish soldiers fought bare-chested, even though many of them were novices.

Puello, despite his wounds and setbacks, regretted not having found death there, because his commitment and courage never wavered in the fight to defend national integrity and the peace of the homeland.