Answer:
the growing power of former indentured servants
Smallpox took its toll on the Aztecs in several ways. First, it killed many of its victims outright, particularly infants and young children.
Millions of people moved during the Industrial Revolution. Some simply moved from a village to a town in the hope of finding work whilst others moved from one country to another in search of a better way of life. Some had no choice, transportation was a punishment for some crimes.
Citizens suddenly got fair trials where actual justice would be served