Can someone tell me about these prisons: The Hulks, Newgate, and Marshalsea?

Answer 1

In the 19th century the Hulks were old warships which were demasted and moored in the River Thames and other places to use as prisons because the usual prisons were too full.
The Marshalsea was a prison for debtors where they stayed until they paid their debt or somebody paid it for them.
Newgate was a prison for thieves and robbers etc. and was one of the worst.