In “The Last Gasp”, Scott Christianson, the author of a new book on the history of the gas chamber, reflects on that subject and capital punishment in general, though not with as much detail as one would like. This claim surprised me: the gas chamber was invented in the twenties, argues Christianson, and
After WWI, which saw the first widespread use of poison gases, it became a method of execution that was actively promoted by Americans who were part of the eugenics movement. They advocated the use of the gas chamber to kill not only criminals but other classes of individuals who were deemed to be unfit or undesirable. There were industrial forces at work as well — businesspeople who wanted to use some of these poisons for fumigation and other purposes — which helped increase interest in the idea of death by gas.
It caught on because it “was thought to kill people very quickly and painlessly. But, belatedly, it was discovered that death by gas was not nearly as fast or as painless as had been assumed,” and in 1994 a judge declared it unconstitutional. But before that, after the moratorium on executions in the seventies, President Reagan suggested lethal injections and
This came at a fortuitous time for conservatives who were beginning to make capital punishment one of their main political issues. They realized that a lot of people were still squeamish about capital punishment based on the experience of the gas chamber and other methods. So lethal injection helped to placate that uneasiness on the part of the American public.