"IN 1850 IN LONDON, by an Act of Parliament, the singular pronoun ‘he’ was finally, legally, crowned. “In all acts,” the Act pronounced, “words importing the masculine gender shall be deemed and taken to include females.” According to the linguist Ann Bodine, the law was introduced “for the shortening of the language used in Acts of Parliament,” and was intended to relieve some of the burden of verbosity demanded by legal precision. Of particular weight, apparently, was the need to write “he or she” when referring to individuals of unknown gender. Perhaps too, having to intone “he or she,” often repetitively, when reading such acts aloud was felt to impede member eloquence; what politico would want to invite bruises to both vanity and persuasion? Thus for motives practical and egotistic, and for patriarchal ones too, “she” was voted off the island."
Dana Levin tackles pronouns in LARB.