The word penitentiary was first used to mean “house of correction” in 1806. So when the Lieutenant Governor of Tasmania (known at the time as Van Diemen’s Land) decided to consolidate the colony’s penal settlements into one location, the inclusion of a penitentiary was fairly novel.
In fact, the rise of the penitentiary was part of the reform movements of the era, when reform societies were working to change and improve the lots of people trapped in lives of poverty or crime. The word was originally used to describe an asylum for prostitutes, where the women were not prisoners, but were actually given a safe haven, where they could be educated and reformed, so they could return to society. Many of the penitentiaries of this era were tremendously successful. (The word penitentiary came from the idea of rescuing penitents, those who regretted their lifestyles and wished to change.) Soon, the idea grew from rescuing prostitutes to rescuing anyone who wanted to escape a life on the streets.
It is because of this different concept of penitentiary that Port Arthur had both a penitentiary and a prison—they were not the same thing. It was with the idea of making useful citizens of transported convicts that the penitentiary was created. It was so good at this that Charles Darwin, when he visited, wrote with admiration of its unparalleled success in creating “active citizens” of a “new and splendid country.”
In the photo of the Port Arthur settlement below, the penitentiary is the massive building that dominates the scene.
Port Arthur
Waltzing Australia 
Well, you learn something new every day. I love words, but for some reason had never really thought about the origin of the word “penitentiary”. Thanks for all that. I’m not sure that Port Arthur was among our most successful penitentiaries, but it sure is a gorgeous place to visit, particularly when the sun hits that lovely sandstone.
It may not seem successful to us now, but at the time, when the concept was new, it was considered pretty amazing — “unparalleled in history” was Charles Darwin’s assessment. Everything has to start somewhere—and if it was, as Darwin wrote, creating “active citizens,” then I wonder if it wasn’t doing a better job than some prisons are today.