Usage of the gas chamber for the death penalty in the United States.

  State uses only this method.
  State uses this method primarily but has secondary methods.
  State uses this as a secondary method.
  State once used this method, but doesn't anymore.
  State has never used this method.
Map from File:Blank US Map.svg by Theshibboleth.
Information from US gas chamber usage.png by Evil Monkey and Shadowlink1014 who credited deathpenaltyinfo.msu.edu as the source.
New colours by MissMJ
Combined by Lokal_Profil
Lokal_Profil