He studied law at Berlin and Heidelberg, and afterwards practised in his native city. He was, however, generally more interested in politics and literature than law.
He was attracted by the social democratic labour movement and after the death of Ferdinand Lassalle, in 1864, he became president of the General Working-men's Union of Germany, and in this capacity edited the Sozialdemokrat, which brought him into frequent trouble with the Prussian government.
He was arrested and charged with the crime of homosexuality but key people within the Social Democrats still supported him.
In 1867 he was elected to the parliament of the North German Federation. In 1868, he coined the term "democratic centralization" to describe the structure of his organization. On his failure to secure election to the German Reichstag in 1871, he resigned the presidency of the Labour Union, and retired from political life.