f conflict between labor and management occasioned by the many attempts of the United Mine Workers of America to organize Harlan's miners during the New Deal Era. Harlan County, Kentucky was the last major anti-union bastion in the Appalachian coalfield. The story of the organization of the county's coal mines by the United Mine Workers of America is largely confined to the decade of the 1930's. The most serious union campaigns occurred in 1931-32, after the passage of the National Industrial Recovery Act in 1933, and following the enactment of the National Labor Relations Act in 1935. Finally, after almost a decade of labor strife, the Federal Government intervened following the Supreme Court decision in the case, N.L.R.B. v. Jones & Laughlin Steel Corporation (301 U.S.1), on April 12, 1937 which upheld the National Labor Relations Act. After a year of federal inquiry, culminating in the Mary Helen conspiracy trial at London, Kentucky, Harlan's miners could join the UMWA openly and without fear of recrimination.