Drywall is a man-made building material used in the construction of the interior walls of homes and buildings. Also sometimes called "gypsum board," "plasterboard" or "sheetrock," the material is made from forming a mixture of gypsum plaster mixed with fiber (usually shredded paper and/or fiberglass), a foaming agent, mildew and fire-resitant additives, and water. The mix is sandwiched between two sheets of tough paper mat or fiberglass, and when dried becomes stiff enough to use as a building material. The use of this material is the world-wide status quo. North America is the largest user, with a total wallboard capacity of 40 billion square feet per year. And in developing countries, it's demand as a construction medium is rapidly accelerating.
However, at the beginning of the 20th century the insides of homes and buildings were obviously not made of drywall. Interior walls were routinely plastered - at the time a ritualistic, laboriously tedious (and expensive) process. To plaster the interior of a structure, elaborate wooden lathes had to be installed along every wall and ceiling surface. These lathes acted as a kind of casting mold. Three separate layers of plaster (a 'scratch coat,' 'brown coat' and 'skim coat') were thickly packed into them at separate times, with the drying time between each layer being anywhere from four days to over a week. Each layer had to be completely dry before the next could be started. When done correctly the effect was beautiful, but the process was a brunt. Wall plastering prevented any work from being done in the home while the drying took place - halting overall progress for a month or more. Also, if mistakes were made (which wouldn't be apparent until the whole thing was completed) it all had to be started again from scratch.
At one point in 1916, the Chicago-based United States Gypsum Company had quietly introduced a new building material called "pyrobar," a gypsum-based, fireproof material sectioned into tiles. This eventually transformed into larger, multilayered paper and plaster sheets called "sackett board" (a result of them purchasing the Sackett Plaster Board Company in 1909, who had technically invented the layering process). Eventually U.S.G.C. changed the board into just one layer of gypsum sandwiched between two sheets of tough paper. Thinking of the product's image, the company decided to name the product "sheetrock." U.S.G.C. tried unsuccessfully for two decades to introduce sheetrock to a wide market, even convincing the creators of the 1933-34 Chicago World's Fair to use it in the construction of its universally-gawked buildings. But in the 1920's and (remarkably) the 1930's, the wide-spread use of sheetrock for home building was held back by it's reputation as an anti-status symbol; nobody wanted to live in homes surrounded by a "cheap," quick-fix walls.
When World War II hit, the government's need for an inexpensive and streamlined building process became a priority. Suddenly "cheap" and quick-fix became the ultimate status symbol; patriotic. Homes began to go up in one-hundredth of the time. A large sheet of drywall could be nailed up to the inside of a home's frame, tape could cover the nail holes, and a layer of plaster (or just paint) could be quickly trowelled on to hide the process. What took an eternity before suddenly took several hours. Whereas a contractor beforehand could construct maybe four or five homes a year using the old paster method, the use of drywall meant that he could now make hundreds, maybe even thousands
The popularity of drywall had originated as a temporary stop-gap when a quick, efficient substitute was needed amongst America's focused priotities in wartime. However, when the war ended, business-minded home builders were in no rush whatsoever to return to the old, time-devouring plastering method (which survives today as a specialized craft). Coincidentally, fate was eventually even more generous to drywall; its acceptance had arrived right at the first introduction of popular modern architecture styles, and the suburban boom. Home buyers were suddenly passing over pre-war decorative structures with exacting, fussy moldings - and enthusiastically seeking out homes with flat, minimal surfaces. Drywall was now unstoppable.
The proliferation of tract-home "sprawl" neighborhoods (which exploded in the 1950's and continues globally today with the wide-spread popularity of "McMansions') was immeasurably fueled by the slightly premature, but eventually triumphant introduction of this unique building material by the United States Gypsum Company in 1916.