Declaration of Independence
The Declaration of Independence by the British Empires' thirteen American Colonies was a boost to the enlightenment ideas of libirty for all men. When Thomas Jefferson wrote this document he realized that it was very unlikely that the slaves within the colonies would see this new found libirty. That being the case, it would not stop anti-slavery forces from trying to utilize the language for their cause.
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. Preamble to the Declaration of Independence