The Library of Congress Online Catalog is the main access point for the Library's collections. Looking for something specific? Just browsing? Either way, you will need to search the catalog to determine the items location and availability. As an interdisciplinary subject, you can find relevant materials in the classified collections from A-Z. Searching by Subject Heading, keyword, or with bibliographic information is likely to yield the best results.

It's important to note that the terms homosexual/heterosexual did not exist until 1868, so for earlier research, you will want to develop a list of historical vocabulary and vernacular. The first uses of the homo/heterosexual term is often considered to be the printing of an 1869 pamphlet by Kertbeny, Károly Maria, 1824-1882. The terms caught on after the work of Kertbeny appeared in the sexology periodical Jahrbuhch Fur Sexuelle Zwischenstufen. Havelock Ellis was an earlier adopter of the terms, further securing it's vernacular use. To find information or primary sources on a specific subject, especially for newspapers and periodicals, it is highly recommended that you consult subject indexes where available (For example, (An Index to The Advocate: The National Gay Newsmagazine). 

Browse the Library of Congress Online Catalog for materials related to the following general subject headings:

• Sexual orientation.
• Asexuality (Sexual orientation).
• Bisexuality.
• Gays.
• Lesbians.
• Gender identity.
• Gender nonconformity.
• Intersex people.
• Transgender people. 
• Queer theory.
• Gender nonconformity.
• Gay rights.
• Non-monogamous relationships.
• Sexual behavior.
• Sexology--History.
• Sexual orientation--Fiction.
• Sexual minority community.