League of the Just
In 1846, in Brussels, Wolff became a close friend of Karl Marx and Friedrich Engels. He was active in the Brussels Communist Correspondence Committee and a member of the League of the Just in addition to being co-founder of the League of Communists in 1848 as a member of its central authority. He served as an editor of the "Neue Rheinische Zeitung" in 1848-9 and as a member of the Frankfurt National Assembly.