The United Venstre, a federation of various Venstre groupings in the Danish Parliament, was founded on June 30, 1870. This makes Venstre the oldest political party in Denmark. Venstre was the first democratic party in Denmark and was represented in the provincial assemblies at the beginning of the 19th century and in the first directly elected parliament in 1849. Venstre has existed as an organized party since 1870.

Until the first democratically elected government of 1901, the political work of the party focused on two areas.

Firstly, the party campaign for parliamentary democracy and universal suffrage, irrespective of earnings, educations, sex etc. The campaign was successful - parliamentary democracy was introduced in 1901 and women were given the vote in 1915.

Secondly, the party favoured liberalising the church, school, adult education, local councils, cooperative movements, etc.