late 15c., "according to fixed laws" (rather than unlimited power of a ruler); 1580s, "in a politic manner;" 1630s "in a political manner," from politic or political + -ly (2). The first sense is obsolete, the second rare or archaic. Politically correct is attested in prevailing current sense by 1970; abbreviation P.C. is from 1986.
[T]here is no doubt that political correctness refers to the political movement and phenomenon, which began in the USA, with the aim to enforce a set of ideologies and views on gender, race and other minorities. Political correctness refers to language and ideas that may cause offence to some identity groups like women and aims at giving preferential treatment to members of those social groups in schools and universities. [Thuy Nguyen, "Political Correctness in the English Language,"2007]