How did the Industrial Revolution play a part in A Christmas Carol?

The Industrial Revolution acts as a back-drop for the story and helps to craft some of the characters that Scrooge has financial power to help or hurt.

Our own study guide says:

In the mid-nineteenth century, London was a crowded, dirty place, a fact that no one did more to publicize than Dickens himself. Industries were not regulated, and widespread pollution and exploitation of the work force resulted. Laborers, many of them children, were...

The Industrial Revolution acts as a back-drop for the story and helps to craft some of the characters that Scrooge has financial power to help or hurt.

Our own study guide says:

In the mid-nineteenth century, London was a crowded, dirty place, a fact that no one did more to publicize than Dickens himself. Industries were not regulated, and widespread pollution and exploitation of the work force resulted. Laborers, many of them children, were required to work fourteen-hour days in order to help their families pay bills; if a family was unable to make ends meet, they might end up in Debtor's Prison—as Dickens' family did when he was twelve. (A Christmas Carol Analysis)

In Stave One we see characters who are responding directly to the circumstances that are described above. There are two men from a charity that ask Scrooge for donations and he replies by asking them, "are there no prisons?" referring to the debtors' prisons people went to when they could not pay their bills. He feels people who are poor are also "idle," and this is simply not the case. In this stave we also meet Bob Cratchit who, although he is not laboring away in a factory somewhere, does work long hours for Mr. Scrooge, in a very cold office he is not allowed to heat, where he is underpaid and made to feel guilty for asking for time off for Christmas. This employer/employee relationship represents the unfair working conditions of many people during the Industrial Revolution, where they had to work a lot in order to barely make ends meet or not meet at all. They often had employers who did not care and simply viewed them as another number, just as Scrooge views everyone he sees. 

Ultimately, Scrooge represents the cold, inhuman wealth of the Industrial Revolution, and those around him represent the victims of the industrial age. The Industrial Revolution was full of haves and have-nots, and Scrooge has the ability to make life easier for many, but at the beginning of the story he chooses not to do so because he values money over relationships.