Traditional attitude towards homosexuality in the Western world was influenced by the ideals of Christianity. because it cannot result in reproduction it was punishable.
This belief penetrated American society and homosexuality was seen as an abnormal phenomenon. Secondly, the studies of homosexuality in the late 19th century focused on the relation of sexual criminals and homosexuality. It resulted in the lack of studies of behavior on normal homosexuals and APA has categorized it as a mental disorder in the 1950's.
However, the issue of homosexuality gained fire and the researches proved that it is not a disorder therefore it should be de-medicalized.
