At the time, the Anti-Socialist Laws made trade unions illegal, but the Travel Support Association fulfilled some of the same role.
Stühmer was drawn to the potential of trade unions to improve pay and working conditions, and in 1888 he moved to Hamburg, then the centre of the German labour movement.
[1] In 1888, the German Union of Tailors was formed, and Stühmer was appointed as its secretary, then soon moved to become its Hamburg branch representative.
[1] The international became moribund at the start of World War I, but Stühmer remained leader of the tailors, in what became the German Clothing Workers' Union.
He stood down as union leader in 1920, but served on the Reich Economic Council, and wrote a history of the German clothing movement, covering 1888 until 1928.