The leaders of the party, founded on platforms of patriotism, Estonian independence, and social justice, made a major contribution to the drafting of the first (1920) Constitution of Estonia.
At this time, the party was named the Estonian Social Democratic Workers Unity (Eesti Sotsiaaldemokraatlik Tööliste Ühendus).
Their newspapers were closed, their politicians were forced to emigrate (Peeter Speek and Mihkel Martna) or prosecute in underground[clarification needed] (August Rei).
Their views were patriotic and they fought for Estonian independence and social justice.
In 1919, they changed their name to the Estonian Social Democratic Workers Party (Eesti Sotsiaaldemokraatlik Tööliste Partei) and won the Constituent Assembly elections with 41 of the 120 seats.