The party, was formed in reaction to the post civil war success of the National Liberation Party. It was formed from the old National Republican Party, led by former president Rafael Ángel Calderón Guardia and the National Union Party, headed by former president Otilio Ulate Blanco, joined by a few minor parties. Calderón Guardia quickly took control of the party. The party was highly personalist, and sometimes the party was referred to as the Calderonistas.