@hightor,
In fact, according to Wikipedia, citing "Findlaw-dot-com," the term poloitically correct was first used in a 1793 Supreme Court ruling:
Quote: Associate Justice James Wilson, of the U.S. Supreme Court comments: "The states, rather than the People, for whose sakes the States exist, are frequently the objects which attract and arrest our principal attention... Sentiments and expressions of this inaccurate kind prevail in our common, even in our convivial, language. Is a toast asked? 'The United States', instead of the 'People of the United States', is the toast given. This is not politically correct." Chisholm v. Georgia, 2 U.S. (2 Dall.) 419 (1793)
In fact, the Wikipedia article goes on to cite published uses of the term in the 1980s and -90s. That is misleading. The term was in common use from the late 1960s onward among members of the left. The idea then was to unite the disparate factions of the left, and to avoid criticisms which would hamper that effort. Therefore, it was not politically correct to call the Black Panthers misogynist; it was not politically correct to criticize feminists for misandry; it was not politically correct to describe the American Indian Movement as violent. (The same applied to the Weathermen originally, but after the bombing of a building at the University of Wisconsin in 1970, which killed one researcher and injured three others, even the most radical members of the left distanced themselves from the Weather Underground.) The term was in common use in the so-called counter culture as early as 1968, and its use grew from 1970 onward. It just took a decade or so for other people, especially those wishing to sell newspapers or books, to notice.