The phrase "All men are created equal" is arguably the single most well-known in any of America's political documents, since the idea it expresses is generally considered the foundation of American democracy. The phrase in context in the opening of the Declaration of Independence reads as follows:
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.

These statements illustrate the idea of natural rights, a philosophical concept coming into favor in America as well as abroad. Many of the ideas in the Declaration were, in fact, borrowed from John Locke, a prominent philosopher of the time. (In fact, Jefferson was accused of quoting him verbatum!)

The Declaration was penned by Thomas Jefferson in 1776.