In the early 1850s English journalist Henry Mayhew began visiting London's East End documenting the lives of the poor for Punch, the humor magazine he founded in 1841.
He interviewed everyone—beggars, street-entertainers (such as Punch and Judy men), market traders, prostitutes, labourers, sweatshop workers, even down to the "mudlarks" who searched the stinking mud on the banks of the River Thames for wood, metal, rope and coal from passing ships, and the "pure-finders" who gathered dog feces to sell to tanners.
He described their clothes, how and where they lived, their entertainments and customs, and made detailed estimates of the numbers and incomes of those practicing each trade. The books make fascinating reading, showing how marginal and precarious many peoples lives were, in what, at that time, must have been the richest city in the world.
Now, the University of Virginia has made Mayhew's profiles of these folks available online. It's a fun read. Link