The modern politically correct movement began at the University of Wisconsin-Madison, which is one of the most liberal colleges in the United States. Political correctness is a liberal degrading of the freedom of speech. George Orwell’s Nineteen Eighty-Four famously incorporated the notion of limiting thought through language (see Newspeak). Words or actions that violate political correctness are called politically incorrect.
At American universities, liberals began imposing political correctness to prevent recognition of differences among gender, religion, belief system, sexual orientation and nationality. In the 1960s, feminists began to demand that the neutral pronouns he, him and his be replaced with expressions like “he or she”, “him or her”, “them”, etc, even though the last one is actually grammatically incorrect. They argued that no one would be able to understand that the masculine gender included the feminine gender in neutral contexts. But this was just part of their campaign to redefine the social roles traditionally associated with masculinity and femininity. In science, political correctness punishes anyone who criticizes the theory of evolution, the theory of relativity, or liberal dogma about global warming.
Political correctness or P.C. also means the alteration of one’s choice of words in order to avoid either offending a group of people or reinforcing a stereotype considered to be disadvantageous to the group. More specifically, groups which (or whose putative leaders or other activists) claim some status as systemically oppressed or discriminated against will periodically attempt to change the terms by which they are referred to and demand that society as a whole change its usage of words as well. Conservapedia