Common Sense
From Conservapedia
Common Sense was a pamphlet written and published (anonymously) by Thomas Paine in January of 1776. It denounced British rule over the thirteen colonies. The pamphlet was written in a language that spoke to the common man, and was immensely popular. It was strongly influential in fostering the desire to be independent from the British monarchy.
Common Sense achieved a feat accomplished by no other work except the Bible: sales of Common Sense totaled half of the number of people who could read in the American colonies. This work, above all others, created an American identity among colonists.