He was born into a middle-class, literary family in New Jersey and studied Law before devoting his life to writing and editing magazines. Initially Stevenson wrote books for boys, centering on romantic teenage friendships. He reviewed musical performances for a NYC paper and after 1900 spent much of his time abroad.

In the first decade of the twntieth century he also published a series of texts that were overtly homosexual, under the pseudonym Xavier Mayne. Imre: A Memorandum is one of the first openly gay American novels with a happy ending.

The quotation on the title page reads: "Before we loathe the homosexual as anarchist against Nature, as renegade toward religion, as pariah in society, as monster in immorality, as criminal in law, let us feel sure that we have considered well whatever the complex mystery of Life presents as his defense ..."

He then moved to Italy, where the law was more lenient on homosexuality.

Imre: A Memorandum is one of the earliest novels with positive homosexual characters, and is especially notable for its happy ending. The story is more of a discourse about homosexuality and serves somewhat as a precursor to the author's later study, The Intersexes. The plot - Oswald, a British aristocrat, meets the Hungarian soldier Imre in Budapest, and they develop a friendship. After some time, Oswald confesses his homosexuality and fears losing his new friend, but Imre's own confession changes both their lives.

Intersexes was originally published at Naples, Italy, in 1906 under the alias Xavier Mayne, in a private edition of 125 copies. Its special interest for us is that the author was a gay man of wide same-sex experience and wide acquaintance with other homosexuals, both European and American, many of whose sexual biographies he records. He concludes that homosexuality is natural, necessary, and legitimate.

He defined an homosexual as "a human being that is more or less perfectly, even distinctively, masculine in physique; often a virile type of fine intellectual, oral and aesthetic sensibilities: but who, through an inborn or later-developed preference feels sexual passion for the male human species. His sexual preference may quite exclude any desire for the female sex: or may exist concurrently with that instinct".

At the end of Intersexes, he talks about the "Gay Capitals" of the US and his list includes: NYC, Chicago, SF, NO, Boston, Philadelphia, DC, St Louis and Milwaukee. Except for the last of these, that list makes sense. It is surprising that Los Angeles is omitted. However, he was writing before the development of the cinema in SW CA.

In 1913 Stevenson published a collection of short stories, including homoerotic ones. By this time he had already moved to Europe. He wrote less and less and died in Lausanne, in Switzerland.