19th century. Slate has also been quarried at Swithland in Leicestershire. There are considerable workings in Cumbria. During the last 500 years, much slate extraction has taken place in the Lake District at both surface quarries and underground mines. The major workings are: Broughton Moor Old Man Complex (Coniston); Cove Quarries (south of Coniston Old Man) Elterwater Quarries Hodge Close Honister Slate Mine (including Yew Crag and Dubs) Kentmere Workings Kirkby Moor (Burlington Slate Quarries) Petts, Kirkstone Little Langdale Quarries Skiddaw Slate Tilberthwaite Common Wood, Ulpha Slate was also quarried in Scotland. Slate industry in North America Slate was first quarried in the United States as early as 1734 along the Pennsylvania Maryland border; however, it was not until 1785 that the first commercial slate quarry was opened in the United States, by William Docher in Peach Bottom Township, Pennsylvania. Production was limited to that which could be consumed in local markets until the middle of the nineteenth century. The slate industry in the United States has existed in several locations in the country including areas in the western states, however the majority of slate has come from three principal regions along the Great Valley of the Appalachian Mountains. Of those regions, the Taconic Mountains region of Vermont and New York, as well as Lancaster, Lehigh and Northampton counties in Pennsylvania all still have active quarries. The Pennsylvania Historical and Museum Commission states that in the Slateford Water Gap area the first verified quarry started some time around 1808 . The industry in this region of Pennsylvania spread across the northern edges of both Lehigh and Northampton counties which contain between them the remains of approximately 400 individual quarries. The origins of quarrying in the Lehigh Valley are obscured by conflicting evidence, although it is safest to say that it started near the town of Slateford in the early Nineteenth Century and moved toward Bangor over a fifty-year period. By 1929, the value of slate production in Pennsylvania was approximately 5 million dollars, accounting for almost half of the 11 million dollar value of slate production for the entire United States. Quarries in this region of the country remained active throughout the first quarter of the 20th century producing roofing slate, slate for electrical uses, as well as being the largest producer of school slates and chalkboards in the country. The Slatington Slate Trade report for January 4 of 1880