Late 19th century/early 20th century. It's why a number of the prison systems in the east coast are called "Department of Corrections", and the facilities themselves often referred to as "penitentiaries".
The Boston municipal jail was shut down a couple of decades ago but when it was built about a century ago it was intended to be enlightened, providing the prisoners with light, fresh air, and exercise and allowing prisoners some internal liberty while being observed. By modern standards it wasn't a very nice place but at the time it was intentionally much better than the contemporary standard.
That period was the most revolutionary of any in the US's history, with many things under experimentation. The "initiative" (i.e. referendum) system used in various western states dates from this period for the same reason, and which even the name demonstrates.
The Boston municipal jail was shut down a couple of decades ago but when it was built about a century ago it was intended to be enlightened, providing the prisoners with light, fresh air, and exercise and allowing prisoners some internal liberty while being observed. By modern standards it wasn't a very nice place but at the time it was intentionally much better than the contemporary standard.
That period was the most revolutionary of any in the US's history, with many things under experimentation. The "initiative" (i.e. referendum) system used in various western states dates from this period for the same reason, and which even the name demonstrates.