[9] During this time, he served on several federal commissions, including an arbitration panel which settled a strike by 1,800 streetcar conductors in Pittsburgh, Pennsylvania, in 1934.

[1] In 1935, President Franklin D. Roosevelt named Madden the first Chairman of the newly formed National Labor Relations Board (NLRB).

[7][10] Madden supported the expanded powers of the NLRB; he had observed the operations of the labor clauses of the previously existing National Industrial Relations Act, which were often stymied by employer refusal to negotiate with union representatives who didn't work for them.

[7] The United States Department of Justice and NLRB legal staff wanted the Supreme Court to rule as quickly as possible on the constitutionality of the NLRA.

[8][14][15] The Supreme Court eventually upheld the NLRA in NLRB v. Jones & Laughlin Steel Corp., 301 U.S. 1 (1937),[7] and Madden personally argued the case (along with NLRB General Counsel Charles Fahy and Charles Edward Wyzanski Jr., a special assistant in the office of the United States Solicitor General) before the Court.

[17] The ruling marked the Court's abandonment of Lochner era jurisprudence and led to a series of cases upholding New Deal legislation.

[18] Madden continued to strategically guide the NLRB's legal efforts to strengthen the courts' view of the NLRA and the Board's actions.

[7] Additionally, the Board won all 30 injunction and all 16 representation cases before the lower courts, a rate of success unequaled by any other federal agency.

[20] Initially, the NLRB held[21] in 1937 that workers themselves should determine whether they wished to be organized by craft or industry, a compromise acceptable to both the AFL and the CIO.

[7][19] It adopted another resolution in October 1938 charging the NLRB and Madden with perverting the law and harboring prejudice against craft unions.

[7] In June 1938, the House Un-American Activities Committee (led by Chairman Martin Dies, Jr.) heard testimony from AFL leader John P. Frey, who accused Madden of staffing the NLRB with communists.

[5][20][23][24] The allegations were true, in at least one case: Nathan Witt, the NLRB's executive secretary and the man to whom Madden had delegated most administrative functions, was a member of the Communist Party of the United States.

[7][13][35] In an attempt to defuse the legislative crisis, Madden fired 53 staff and forced another five to resign, and decentralized the NLRB's trial process to give regional directors and field agents more authority.

[10][24] Madden entered political limbo: His five-year term as an NLRB Member expired on August 27, 1940, but Roosevelt did not reappoint him or anyone else to the position.

[40] On October 9, 1940, Secretary of Labor Perkins announced Madden would go to Canada to study that country's problems in boosting defense production.

[28][42] Although the United States Senate Committee on the Judiciary favorably reported Madden's nomination to the floor (almost without discussion or comment),[43] Republican Senators Robert A. Taft and Arthur H. Vandenberg, along with other Republicans, attempted to hold up the nomination on procedural grounds as a means of expressing their anger at what they believed was Madden's pro-labor administration of the National Labor Relations Act.

[3] He was appointed Associate Director of the legal staff of the Office of Military Government, United States in 1946,[47][48] and for his service received the Medal of Freedom in 1947.

[49] He also was part of a team which traveled with Generals Dwight Eisenhower and Lucius D. Clay to the Potsdam Conference to provide legal assistance.