[1] Alfaro was born in Alajuela, Costa Rica, then part of the Viceroyalty of New Spain, on March 20, 1799, to his parents Juan Antonio Alfaro y Arias and María Damiana Zamora y Flores.

He owned lands devoted to coffee plantation and a sawmill in Itiquís near Alajuela.

On June 7, 1846, after a coup d'état Alfaro was again declared Provisional Head of State.

During this administration Puntarenas was declared a free port, the 1847 Constitution was emitted and a failed diplomatic mission with Nicaragua was launched in a second attempt to sign a border agreement with this country (a previous attempt by Braulio Carrillo in 1838 had also failed).

Although he lost the 1847 elections to José María Castro Madriz he won the office of Vice President for the next term.