This large subseries includes charges of Unfair Labor Practices based on alleged violation of the National Labor Relations Act. These cases were filed after the Act was amended by the Taft-Hartley Act of 1947. Also found here are petitions for representation elections. Many NLRB hearings went into federal court for enforcement. The biggest case in this collection, Rotan v. MCS (NLRB #19-CA-186), became NLRB v. PASA & MCS in the U.S. Circuit Court of Appeals (#13386).