The phrase or idea that "all men are created equal" has been up for debate for decades In the United States Declaration of independence written in 1776. The remark is said to have come from Filippo Mazzei an Italian physician and confident to Thomas Jefferson. Jefferson often deliberated with Mazzei and traded ideas. Jefferson and Mazzei felt the phrase was fitting and essential as the opening of the declaration of Independence:
When, in the course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the laws of nature and of nature’s God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.
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. Those to secure these rights, governments are instituted among men, deriving their just powers from the consent of the governed. That whenever any form of government becomes destructive to these ends, it is the right of the people to alter or to abolish it, and to institute new government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their safety and happiness. Prudence, indeed, will dictate that governments long established should not be changed for light and transient causes; and accordingly all experience hath shown that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same object evinces a design to reduce them under absolute despotism, it is their right, it is their duty, to throw off such government, and to provide new guards for their future security.1 – U.S. Declaration of Independence July 4th 1776 -
There was much debate about this phrase as most members of congress owned slaves including Thomas Jefferson. The Declaration was altered from its original version as it depicted the Slave Trade and the ownership of slaves in a disparaging light.