It's also impossible to say whether the prosperity was due to the free market and lack of regulations, the industrial revolution and development of steam power or the rise of the middle class and their increased free time/income.
I suspect that mostly it was technology, similar to what's happening in developing nations right now, rather than any free markets.
Do you have any support for that assertion? The poor themselves decided en masse to move from village to city at the time, which seems to indicate the contrary. Yes, in the city they were also much more visible to literate observers who would write about their misery, but who knows what those same observers might have exposed if they had lived in a village instead. The people who knew both sides of the situation, certainly seemed to vote with their feet for the industrialized cities. We see the same phenomenon at work in China nowadays.
In many cases they hardly "decided"; they were en masse kicked off the land, so had no real choice. See: http://en.wikipedia.org/wiki/Inclosure_Acts
You have the same mechanism at work today, in slums in India, South America and so on. The draw is the possibility of being better off and having more opportunity than you would in a rural area, but it doesn't always end up that way.
But we're getting off the point, which is that a free market doesn't give you "unprecedented human health and prosperity" - the best that you can argue is that it's one of the preconditions (but not the only one).
How about an eyewitness account, from 1902:
