▁and ▁paper ▁that ▁could ▁be ▁joined ▁flush ▁along ▁a ▁wall ▁with ▁a ▁relatively ▁smooth ▁surface . ▁Origin ally ▁called ▁Adam ant ▁P anel ▁Board , ▁the ▁product ▁became ▁known ▁as ▁She et rock ▁in ▁ 1 9 1 7 . ▁ ▁By ▁the ▁ 1 9 3 0 s , ▁the ▁company ' s ▁policy ▁of ▁diffusion ▁of ▁manufact uring ▁facilities , ▁vertical ▁integration ▁and ▁product ▁divers ification ▁allowed ▁it ▁to ▁operate ▁profit ably ▁every ▁year ▁during ▁the ▁Great ▁De pression . ▁The ▁ 1 9 3 3 ▁Chicago ▁World ’ s ▁Fair ▁featured ▁buildings ▁made ▁almost ▁entirely ▁out ▁of ▁S HE ET RO CK ▁pan els , ▁which ▁led ▁to ▁the ▁brand ' s ▁first ▁major ▁advert ising ▁campaign . ▁ ▁The ▁ 1 9 5 0 s ▁and ▁ 1 9 6 0 s ▁saw ▁expansion ▁into ▁Mexico ▁and ▁other ▁international ▁mark ets . ▁ ▁Rec ession ▁and ▁its ▁effect ▁on ▁the ▁bottom ▁line ▁domin ated ▁the ▁ 1 9 8 0 s ▁and ▁led ▁to ▁a ▁rest ruct uring ▁of ▁the ▁company . ▁On ▁January ▁ 1 , ▁ 1 9 8 5 , ▁US G ▁Corporation ▁was ▁formed ▁as ▁a ▁holding ▁company ▁ ▁a ▁reverse ▁mer ger ▁in ▁which ▁United ▁States ▁Gy psum ▁Company ▁became ▁one ▁of ▁just ▁nine ▁operating ▁subs idi aries . ▁ ▁In ▁the ▁mid - ▁to ▁late - 1 9 9 0 s , ▁the ▁company ▁inv ested ▁in ▁a ▁significant ▁expansion ▁of ▁its ▁manufact uring ▁network , ▁adding ▁new ▁high - speed ▁wall board