late 1919 had developed into a potentially explosive situation, due to new unionization efforts.

Unionization had always met fierce resistance from coal operators, who used eviction, termination, blacklisting, yellow dog contracts, court injunctions, coercion, and intimidation to prevent workers from joining unions and to stifle union organizers. By the early twentieth century, especially in the eastern United States, coal operators held and exercised exclusive political control and strongly influenced local and state governments, literally dictating state policies that would insure coal profits, prevent labor organization, and guarantee a passive work force. Such tight control was necessary, coal operators maintained, because of the "boom and bust" nature of the coal mining industry, the instability of consumer demand, competition at home and abroad, and constantly fluctuating coal prices. Except for abrief period during the Anthracite Strike of 1902, when the federal government openly sided with labor organizations against recalcitrant mine owners, the companies had successfully resisted attempts by miners to unionize.

In the face of owner opposition, however, miners succeeded in forming unions as early as the 1860s. None of these early organizations gained national stature, recognition, or membership until several merged to form the American Federation of Labor-affiliated United Mine Workers of America (UMW) in 1890. Although the UMW initially favored conference and arbitration techniques rather than strikes, resistance on the part of coal operators compelled the union to adopt strikes as the primary means of obtaining its goals. Traditional miner demands became union demands and included union recognition; the right of workers to join a union, thereby