He joined the labor movement and the Communist Party of Germany.
He joined the Social Democratic Party of Germany in 1914.
In 1945, he joined the Social Democratic Party of Germany.
The year before, he had joined the Social Democratic Party of Germany.
The Communist Party of Germany had been outlawed since 1956.
The following year he became a member of the Communist Party of Germany.
He was also a political activist for the Social Democratic Party of Germany between 1918 and 1933.
In 1929, he joined the Communist Party of Germany.
He joined the Communist Party of Germany in 1931.
The party's predecessor, the Communist Party of Germany, opened its headquarters on the square in 1926.