Conversation so far:
What is Harlot's Progress?
The collection of six scenes was entitled A Harlot's Progress and appeared first as paintings before being published as engravings.
Who drew Harlot's Progress?
In 1731 William Hogarth completed the earliest of his series of moral works, a body of work that led to significant recognition.
How many paintings were there in the Harlot's Progress?
The collection of six scenes was entitled A Harlot's Progress and appeared first as paintings before being published as engravings.

Question: When did he draw it?
Self-contained rewrite: When did William Hogarth draw Harlot's Progress?