The family moved to Berlin, where he attended the Evangelisches Gymnasium zum Grauen Kloster but left school without passing his Abitur.
[4] The first floor of the library housed the official archives of the Social Democratic Party, about 8000 printed and numerous handwritten documents.
The property was transferred to several Social Democratic politicians like Karl Liebknecht, Eduard Bernstein and Paul Singer, which, as private real estate was a binding premise for passive electoral rights, allowed them to be elected to the City council.
[6] Heimann joined the Social Democratic Party of Germany and became a close friend of August Bebel and Paul Singer.
[2] A memorial plaque at the location of the Red Houses, which were destroyed in World War II, the Hugo-Heimann-Bridge, the Hugo Heimann library (closed in 2015) and the Hugo-Heimann-school [9] at Hugo-Heimann-Straße[10] remember him.