In his book What’s Your Pronoun? Beyond He and She, linguist Dennis Baron writes that the pursuit of a singular nongendered pronoun dates back centuries, with dozens of pronouns being coined to fill the gap (including ze, zhe, hir, hem, han, hizzer, hiser, himmer, thon), each with its own origin.
“The fact that gender-neutral pronouns and nonbinary pronouns are invented over and over again, often by people completely unaware of previous attempts to find the missing word, suggests that speakers of English do feel that a word is missing from the set of personal pronouns,” he writes.
Baron also notes that this debate over how to use a singular pronoun outside the gender binary has arisen in some other dialects, such as a French dictionary coining a gender-neutral pronoun, Swedes using the gender-nonspecific pronoun hen, and Spanish speakers drawing attention to the gendered nature of the language’s nouns and articles.
He/him pronouns were historically used as gender-neutral pronouns in legislation and literature, which was, at best, inaccurate and fraught; during the women’s suffrage movement, Susan B. Anthony noted that despite the generic masculine pronouns in criminal laws, it was understood that they still applied to women. But if lawmakers insist on following the letter of the law, Anthony said in an 1873 address, then the corollary would suggest that women should not pay taxes or otherwise be beholden to the legal system.
Baron points to other times throughout US history when a gender-neutral pronoun was sought, including in 1894 when a newspaper needed to refer generically to lawmakers after three women were elected to the Colorado legislature. In 1920, the Sacramento Bee published a headline reading “‘Hir’ Will Be the Bee’s Word for ‘He or She.’” (The paper’s reporters only sporadically used hir in the following years into the 1940s, Baron writes, but it has been revived as a nonbinary pronoun in the 21st century.)
Among the historical uses of the singular they that Baron cites, it’s clear that pushback against it as a singular pronoun is nothing new — even though, as Baron writes, it’s been “good, idiomatic English for 700 years.” President Calvin Coolidge noted in 1926 that no voter should “abdicate their sovereign right of self-government” by failing to vote; his use of the singular they was called by one newspaper a “technically lawless act.”
The 14th edition of the Chicago Manual of Style initially advised writers to use the singular they, noting that it’d been used by Jane Austen, William Shakespeare, and others for centuries. In the 16th edition, Chicago wrote, “Many people substitute the plural they and their for the singular he or she. Although they and their have become common in informal usage, neither is considered acceptable in formal writing.” The latest edition allows for the singular they and other gender-neutral variations and notes that “any such preference should generally be respected.”
Source: https://www.buzzfeed.com/emersonmalone/pronouns-nonbinary-gender-language