New Market is a town in Jefferson County, Tennessee, United States. It is part of the Morristown metropolitan area. The population was 1,334 at the 2010 census and 1,349 at the 2020 census. On September 24, 1904, two passenger trains collided head-on near New Market, killing a large, unknown number of passengers. Different sources give different valu…New Market is a town in Jefferson County, Tennessee, United States. It is part of the Morristown metropolitan area. The population was 1,334 at the 2010 census and 1,349 at the 2020 census. On September 24, 1904, two passenger trains collided head-on near New Market, killing a large, unknown number of passengers. Different sources give different values for the number of deaths, ranging from 54 to 113.