USG Corporation

USG Corporation, also known as United States Gypsum Corporation, is an American company which manufactures construction materials, most notably drywall and joint compound. The company is the largest distributor of wallboard in the United States and the largest manufacturer of gypsum products in North America. It is also a major consumer of synthetic gypsum, a byproduct of flue-gas desulfurization. Its corporate offices are located at 550 West Adams Street in Chicago, Illinois.

USG's most significant brands include Sheetrock Brand Gypsum Panels, Securock Brand Glass-Mat Sheathing, and Sheetrock Brand All Purpose Joint Compound.

In December 2013, Warren Buffett's Berkshire Hathaway became the largest shareholder in the company (holding roughly 30%) when it converted USG convertible notes it had acquired in 2008 to common stock.

In June 2018, USG entered into an agreement to be purchased by the privately held building materials company Knauf. It operates as an independent subsidiary of Knauf and continues to remain headquartered in Chicago, Illinois. The deal closed in April 2019.

In 1890, New York Coal Tar Chemical Company employees Fred L. Kane and Augustine Sackett developed plaster board by strengthening the plaster with Plaster of Paris sandwiched between heavy paper, creating a viable competitor to traditional lime plaster. Sackett patented the new drywall product as Sackett Board in 1894.

Since gypsum was plentiful, available at a relatively low price, and used a simple manufacturing process, new firms flooded and fragmented the market, placing constant downward pressure on prices.^{[citation needed]}

On December 27, 1901, 30 gypsum and plaster companies merged to form the United States Gypsum Company (USG), resulting in the creation of the first nationwide gypsum company in the United States. The new company combined the operations of 37 mining and calcining plants producing agricultural and construction plaster. Directors of the new firm selected B.W. McCausland of Michigan for its first president; in 1905, he was succeeded by his previous Alabaster Company business partner's son, Sewell Avery, who served in the role for 35 years.

In 1909, Avery led the USG acquisition of the Sackett Plaster Board Company, inventor of Sackett Board, which was a panel made of multiple layers of plaster and paper. Patented by USG in 1912, a new manufacturing process produced boards with a single layer of plaster and paper that could be joined flush along a wall with a relatively smooth surface. Originally called Adamant Plaster Board, the product became known as Sheetrock in 1917, with the new term credited to USG sales representative D.L. Hunter of Fort Dodge, Iowa.