A notably generous man, he established a free public school for underprivileged children in the small town of Guáimaro, 70 km (43 mi) southeast of Puerto Príncipe.

Despite the usual public outcry to abolish slavery, Agüero's action was an illegal act, and to escape legal inquiries, he was forced to leave Cuba with his family for the United States; however, the immense love he felt for his homeland brought him back within three months.

[3] After his return, Agüero stayed in his farm "El Redentor", near the town of Guáimaro, while actively participating in clandestine independence movements against Spanish rule.

[3] His armed revolt had failed miserably, but as historian Cento Gomez stated, "it was a ground breaking event in the history of Cuban struggle for independence.

"[3] On August 12, 1851, he was shot by a firing squad of Spanish troops alongside three of his compatriots including José Tomás Betancourt in Puerto Príncipe (today's Camagüey province).

[3] As a consequence of the local anti-colonial tradition, and continental influences, he took up arms and left for the manigua (relatively inaccessible fields and mountains), compromising his social position and economic privileged, to fight against the Colonial Spanish America.

It is said that the houses were left empty as everyone went to their properties in the countryside as a protest for their three fallen companions: Tomás Betancourt, Fernando de Zayas and Miguel Benavides.