What is propaganda? It is information, ideas, or rumors deliberately spread widely to help or harm a person, group, movement, institution,nation, etc.
The Patriots (rebels) used the Boston Massacre to their advantage. The incident was widely reported as an attack on Boston teenagers who were harmlessly throwing snowballs.
This propaganda helped to change the minds of many colonists who were Loyalists of indifferent.
The drawing above was printed in many newspapers and forced some to change their views about King George and the British.
