Armstrong World Industries, Inc. engages in the design, manufacture, and trade of commercial and residential ceiling, wall, and suspension system solutions. It operates through the following segments: Mineral Fiber, Architectural Specialties, and Unallocated Corporate. The Mineral Fiber segment produces suspended mineral fiber and soft fiber ceiling systems for use in commercial and residential settings. The Architectural Specialties segment manufactures and sources ceilings and walls for use in commercial settings. The Unallocated Corporate segment includes assets, liabilities, income, and expenses that have not been allocated to other business segments. The company was founded by Thomas M. Armstrong in 1860 and is headquartered in Lancaster, PA.