In the 1917 split of the Social Democratic Party, Spångberg joined the Communist group headed by Zeth Höglund.

In 1937 August Spångberg travelled with Ture Nerman to Spain to participate in the fight against the Nationalists of General Francisco Franco.

When Spångberg and Nerman return to Sweden soon after, they came home to see their party falling apart in a struggle between Karl Kilbom and Nils Flyg.

During World War II Spångberg participated in the Norwegian resistance movement against the Nazi occupation of Norway.

He helped many people escape Nazis-occupied Norway including Willy Brandt, who would later become the Chancellor of the Federal Republic of Germany.

The Eda Municipality Library in Charlottenberg, Sweden holds a special collection of Augustus Spångberg's parliamentary documents, letters, and literature.

At the age of 82, he authored a novel, Radmannen, the Tale of a Crime [Rådmannen: En historia om ett brott] which dealt with the Unman affair, of the 1950s, in which he had been involved and against which he fought.