Which piece of work is considered to have an impact during the American revolution due to the fact that it was written in a way that average colonists could understand and thereby discuss everyday settings such as taverns and coffee houses?

The piece of work that had a great impact during the American Revolution because it was written in an understandable way was "Common Sense", a pamphlet published by Thomas Paine in 1775-1776.

It read aloud and circulated among public houses, taverns and public meeting places and, written in clear and understandable prose, it presented political and moral arguments for the independence. The text was written in the form of a sermon and while the arguments contained complex political, democratic and moral reflections, it was written to address the common man so anybody could read it, understand it and debate about them.

This addressing style and the readership it achieved made "Common Sense" an impressive piece of propaganda towards American Independence.