John Manville was an American manufacturer known for producing insulation and roofing materials. Founded in 1858, the company became a significant player in the construction industry, particularly for its innovative products that improved energy efficiency in buildings. In the mid-20th century, John Manville faced legal challenges due to the health risks associated with asbestos, a material used in many of its products. This led to bankruptcy in 1982, but the company restructured and continued to operate, focusing on safer alternatives in insulation and construction materials.