Who is Mike the Crossing-Sweep from London Labour and the London Poor and what is their importance?

The only subject named in the book is Mike, a young orphan who worked as a crossing sweep. Mike used a broom to keep an intersection of the street clean, earning tips from people with homes or businesses nearby. His father died when Mike was just a tot. His mother was cheated out of the familiy's property. After Mike's mother died, he lived with his teen sister. However, when she married, her husband did not want the burden of supporting a 12-year-old boy and kicked Mike out. The sister and her husband moved to America.

Mike joined an all-male gang of sweeper youths. They tumbled beside buses, performing cartwheels and back flips. When the bus stopped, passengers frequently gave them tips. The rest of the time, the group swept at specific intersections, earning tips. The group pooled their money for food and a room in a lodging house. When there was not enough money for a room, they slept huddled together under the stone archway of a church door.