As a representative of the Christian trade unions he signed on 15 November 1918 the "Arbeitsgemeinschaftsabkommen" between the employer's association and the trade unions. From 1919-29 he became the head of the Christian German Union Federation. He was from 1919 to 1920 a member of the National Assembly. He belonged to the 'Committee for the preliminary discussion of the draft constitution for the German Empire' of the National Assembly. From March 1919 to November 1921 he was Prussian Minister for People's Welfare. From April to November 1921 he held both the office of the Prussian Minister-president, from April 1929 to March 1930 that of the Minister for Transports, from March 1930 to May 1932, the Minister for employment. As Minister of Labour in the cabinet of his former personal assistant Heinrich Brüning he tried to save at least the basics of the Weimar welfare state under the conditions of the Great Depression. He failed therein because of the resistance of the Heavy industry.
Nazi Regime
Following Hitler's appointment as Chancellor, Stegerwald was attacked by Nazi storm troopers at an election rally in Krefeld on February 21, 1933, while regular police did not interfere In March 1933, he led together with Ludwig Kaas and Albert Hackelsberger negotiations with Adolf Hitler. Afterwards the Centre party agreed to the Enabling Act. From 1933-34 he was indicted, along with Wilhelm Marx and Heinrich Brauns, in the trial of the Cologne Volksverein Verlag in his capacity as board member of the National Association for Catholic Germany. He was on the list of politicians to be purged during the Night of the Long Knives, but was warned about this and disappeared into exile for three months. After the 20 July plot, he was temporarily arrested under the Aktion Gitter. From August 24, October 19, 1944 he was detained by the Gestapo in Würzburg prison. During the time of Nazi Germany he had no influence.
Schnorr, Helmut J.: Adam Stegerwald, Gewerkschafter, Politiker der ersten deutschen Republik. Ein Beitrag zur Geschichte der christlich-sozialen Bewegung in Deutschland. 1966.
Morsey, Rudolf: Zeitgeschichte in Lebensbildern – Aus dem deutschen Katholizismus des 20. Jahrhunderts. Band 1. 1973, S. 216.
Rosenberg, Ludwig, Tacke, Bernhard: Der Weg zur Einheits-Gewerkschaft. Hrsg. DGB-Bundesvorstand. Druck: satz + druck, Düsseldorf 1977.
Forster, Bernhard: Adam Stegerwald. Christlich-nationaler Gewerkschafter, Zentrumspolitiker, Mitbegründer der Unionsparteien. Droste Verlag, Düsseldorf 2003,.