William Blake wrote the poem "London" in the midst of Great Britain's Industrial Revolution in the late 18th century. This transformed Great Britain into a worldwide leader of commerce. It created a prosperous middle class of manufacturers and steady wages for numerous factory workers. However, along with the prosperity came many serious problems. For instance, child labor was ubiquitous and safety standards in factories were horrendous. Although at the time the city of London, as an industrial capital, was being touted as a model of progress, in the poem "London" Blake points out the negative aspects of the Industrial Revolution by highlighting examples of people left in poverty and destitution despite the so-called progress.
Blake speaks of wandering the streets of London and seeing "weakness" and "woe" on every face he passes. He says that even infants are in fear, and that manacles, which are imprisoning chains, shackle people's minds. This can refer to the despair that factory workers feel of ever rising from their sordid state of existence. Chimney-sweepers, who were usually children, cry because of poverty and disease, young women are forced to become harlots, and soldiers shed their blood so that the rich can live in palaces.
To sum up, Blake wants his readers to know that the Industrial Revolution has its dark underside, and the people that are negatively affected by it can be found all over the streets of London.