The group was formed in 1889 after a split from the Opportunist Republicans majority and constituted the parliamentary right-wing after the monarchists' decline during the end of the century.
Depicting Boulanger as "a new Napoleon", the party claimed an agreement between moderate republicans and anti-Bonapartist monarchists reminiscent of the 1863 legislative election.
The chair committee of the Liberal Union was headed by Henri Barboux and composed of prominent personalities including Léon Say, Émile de Marcère, Georges Picot and Anatole Leroy-Beaulieu.
[6] Thanks to the downfall of General Boulanger, accused of conspiracy against the Republic, the moderate republicans won the 1889 legislative election by a landslide and the Liberal Union gained six seats in the Chamber of Deputies.
In the late 1890s, the Liberal Republican Union also lost its free market tradition of protectionism, supported by prominent politician Jules Méline.