Side A: Robinson's Cave. On a forested hillside south of New Straitsville, the spacious 1000 square foot Robinson's Cave offered a secluded location with great acoustics where large groups of Hocking Valley coal miners could meet in secret. Beginning in about 1870, labor-organizing meetings were held at the cave by various emerging unions including the Knights of Labor. New Straitsville resident Christopher Evans, a well-known union organizer, used Robinson's Cave to lead miners throughout the long Hocking Valley Coal Strike of 1884-1885. These meetings gave the miners a voice in the formation of a national organization called the National Federation of Miners and Mine Laborers, later renamed the National Progressive Union. The cave was also where non-union miners met to plan to set the Columbus & Hocking Coal & Iron Company mines on fire in a desperate attempt to end the Hocking Valley Strike. [continued on other side] Side B: Same. [continued from other side] In 1886, the Knights of Labor founded the National District Assembly #135, a rival for the National Federation of Miners and Mine Laborers. Oddly, both headquarters were located in New Straitsville. Dissension between the two groups hurt labor negotiations, but Christopher Evans continued to hold meetings to settle differences. In response to a miner's death in 1889, the feuding miners used Robinson's Cave to reconcile once and for all. Evans called miners together again in 1890 for the first organizational meeting of the United Mine Workers of America, the name formally adopted at their next meeting in Columbus. This series of historic meetings is why Robinson's Cave is referred to as the secret birthplace of the United Mine Workers.