- The goal of the Library's efforts with the Human Sexuality Collection is to encourage the study of sexuality and sexual politics by preserving primary sources that too often are lost. Our attention goes particularly to groups that are excluded from mainstream culture. Through our collecting efforts, we seek to document historical shifts in the social construction of sexuality, primarily in American history from the 19th century onward. We focus on lesbian and gay history and the politics of pornography, both at the national level. Books date mostly from the mid-1800s on; manuscripts and periodicals date mostly from the 1950s on; and audio-visual materials date mostly from the 1970s on.