The party was formed in 1948 in order to support the candidacy of Francisco Javier Arana in the 1950 presidential elections.
[1] However, Arana was killed after threatening to launch a coup in the build-up to the elections, having been considered the main rival to Jacobo Árbenz of the Revolutionary Action Party.
In the 1958 general elections it was part of the alliance nominating José Luis Cruz Salazar, who finished as runner-up to Ydígoras.
In the Congressional elections the PUA ran in an alliance with the Republican Party and Guatemalan Christian Democracy, with the three winning 20 of the 66 seats.
In 1983 the party was re-established by Lionel Sisniega Otero Barrios, a former member of the National Liberation Movement (MLN).