The Westmoreland County coal strike of 1910–1911, or the Westmoreland coal miners' strike, was a strike by coal miners represented by the United Mine Workers of America. The strike is also known as the Slovak Strike because about 70 percent of the miners were Slovak immigrants. It began in Westmoreland County, Pennsylvania, on March 9, 1910, and ended on July 1, 1911. At its height, the strike encompassed 65 mines and 15,000 coal miners. Sixteen people were killed during the strike, nearly all of them striking miners or members of their families. The strike ended in defeat for the union. Background The Irwin gas coal basin is an area in Westmoreland County, Pennsylvania. It encompasses the townships of North Huntingdon, Penn, Sewickley, Salem, South Huntingdon, Hempfield and Irwin, and the boroughs of Murrysville, Export and Delmont. The coal mined in the district was unsuitable for use as coke. However, it was ideal for gasification and conversion into coal gas. Seven companies dominated coal mining in the Irwin Basin in 1910. In 1854, the Westmoreland Coal Company was formed to begin mining coal in the region. In 1905, it bought a controlling interest in Penn Gas Coal, a company established in 1861 to gasify coal. Penn Gas Coal, in turn, had obtained a one-third ownership in the Manor Gas Coal Company. Through these purchases, Westmoreland Coal had a near-monopoly on the gas coal market, and was the largest bituminous coal company in Pennsylvania. In 1892, Robert Jamison and his sons founded the Jamison Coal and Coke Company (originally the Jamison Coal Company). In 1886, the Berwind family and Judge Allison White founded the Berwind-White Coal Mining Co. In 1902, a number of smaller coal gas companies in and around Greensburg, Pennsylvania, merged to form the Keystone Coal and Coke Company. In 1905, Latrobe-Connellsville Coal and Coke Company was formed when Marcus W. Saxman merged three of his wholly owned or controlled coal companies. These companies were very paternalistic. Company towns (colloquially referred to as "coal patches") were established, company stores founded and workers often paid in company scrip. Origins of the strike Coal miners increasingly agitated for improved wages and working conditions after 1900. Miners demanded an eight-hour day and wages equal to those paid in the nearby Pittsburgh coal basin. Since miners were paid by the ton, workers also wanted to standardize the size of coal wagons to ensure they