Interest in large-scale coal mining in Greene County began in 1891 with the purchase of coal lands in townships along the Monongahela River, and speculation peaked from the 1890s into the early 1900s as purchases rose from 9,000 acres in 1893 to more than 50,000 acres in 1894. During the first five years of the 20th century, 40 separate transactions totaled more than 112,000 acres for about seven million dollars. Josiah Van Kirk Thompson of Fayette County had the greatest impact on the future of coal mining there; in December 1899, he and his associates bought more than 60,000 acres and soon controlled more coal acreage than any other company or organization. After Thompson's First National Bank of Uniontown failed in January 1915, widespread financial problems deepened in Greene County and the coal industry. He owned coal and property in Greene County valued at more than 65 million dollars, owed county citizens an estimated seven million dollars, and had not paid taxes for several years. Bankruptcy proceedings in the United States District Court followed, becoming the largest and most complex case in that court and in the country at that time, and his holdings were eventually sold in blocks to steel companies for their own use. Before large commercial operations, settlers and later small companies used drift mining to work coal outcrops along creeks and the Monongahela River, usually for personal use, and in the 1890 census Greene County had no large-scale commercial mines and produced 54,000 tons. Large-scale commercial mining began in 1902 with the opening of the Dilworth Mine near Rices Landing, the first mine in the county supervised and regulated by the Pennsylvania Department of Mines. From 1906 to 1915 the largest mines were the Dilworth, Crucible, and Poland mines. In 1916 Greene County produced more than 800,000 tons of coal and employed more than 700 miners. From 1916 to 1921, the most important period for Greene County coal, World War I increased demand, raised production, opened new mines, and added the mining towns of Nemacolin and Mather. By 1921, 18 mines produced more than two million tons and employed almost 3,000 miners, and in 1927, during the strong coal market of the 1920s, 24 mines produced more than six million tons and employed 4,851 miners.