▁chemical s ▁Category : Reg ulation ▁in ▁the ▁United ▁States <0x0A> </s> ▁Mill bro ok ▁is ▁a ▁g host ▁town ▁in ▁Graham ▁County , ▁Kansas , ▁United ▁States . ▁ ▁History ▁Graham ▁County ▁was ▁organized ▁for ▁administrative ▁purposes ▁on ▁April ▁ 1 , ▁ 1 8 8 0 , ▁with ▁ 1 5 0 0 ▁inhabitants ▁in ▁the ▁county ▁and ▁with ▁the ▁first ▁county ▁seat ▁located ▁at ▁Mill bro ok . ▁The ▁appointed ▁officers ▁were : ▁C ler k , ▁E . ▁P . ▁McC abe ; ▁commission ers , ▁E . ▁C . ▁Mos es ▁and ▁O . ▁G . ▁Nev ins . ▁The ▁first ▁election ▁was ▁held ▁on ▁June ▁ 1 . ▁ ▁Mill bro ok ▁was ▁destroyed ▁by ▁a ▁torn ado ▁on ▁August ▁ 4 , ▁ 1 8 8 7 . ▁ ▁After ▁the ▁T orn ado ▁The ▁county ▁seat ▁was ▁moved ▁to ▁Hill ▁City ▁on ▁March ▁ 1 0 , ▁ 1 8 8 8 . ▁ ▁J . R . ▁Pom ero y , ▁who ▁assist ed ▁Mr . ▁Hill ▁in ▁developing ▁Hill ▁City , ▁don ated ▁most ▁of ▁the ▁tract ▁of ▁land ▁on ▁which ▁the ▁cour th ouse ▁was ▁built . ▁This ▁site ▁is ▁still ▁being ▁used ▁for ▁a ▁modern ▁cour th ouse . ▁ ▁Hill ▁City ▁was ▁chosen ▁as ▁the ▁permanent ▁county ▁seat , ▁and ▁the ▁following ▁officers ▁were ▁elected : ▁Represent ative , ▁J . ▁L . ▁Wal ton ; ▁commission ers , ▁A . ▁Mort on , ▁G . ▁W . ▁More house