In last night's episode, young Annie Reilly tells Detective Kevin Corcoran that she was threatened with being sent to Blackwell's Island. And she was right to be scared: Located in the East River, Blackwell's Island was where New York City had its penitentiary and workhouse.

Blackwell’s Island—named after Robert Blackwell, whose family had farmed on the land— was purchased for $32,500 in 1828, to replace prisoner facilities near Bellevue Hospital. According to NYC Corrections History, the penitentiary was built in 1832 and housed "nearly a thousand inmates, most serving misdemeanor sentences but all were required to perform some daily labor, the tasks varying according to inmate skills and strengths" while a workhouse, built in 1852, had 221 beds for the "punishment of petty violators, many of whom were classified as habitual 'drunks and disorderlies' including several who virtually became permanent residents even though the usual stays were counted in days." The workhouse inmates "were assigned work either in the workhouse shops or at other city institutions."

Besides the penitentiary and workhouse, there was also a lunatic asylum (where patients were abused), a smallpox hospital and an almshouse where the sick, destitute, and homeless were sent. Abandoned children were also sent to the almshouse—here's a report from 1863—and many didn't survive infancy.

Here's a 1903 look at Blackwell's Island:

Now Blackwell's Island is known as Roosevelt Island. With 12,000 residents, it's perhaps most familiar to the public as the place where the tram goes when Spider-Man and the Green Goblin fight: