Some zinesters trace the the word "zine" to 1930s science fiction fanzines. Fanzines are independently published homages to a favorite topic. However, zines can be traced back to even earlier times. In seventeenth century Britain, pamphlets were distributed that promoted moral and political points of view. Within United States’ history, such pamphlets were critical to the American Revolution, the emancipation of slaves, women’s suffrage, the labor movement, and the civil rights movement. Probably the most famous pamphlet in US history is Thomas Paine's Common Sense published in 1776.
In the late 1960s and early 70s fanzines merged with political pamphlets. Thousands of zines, mostly made by young people, commented on the social revolution fueled by the Vietnam War and the Civil Rights movement. It was also during this time that visual artists began to explore the book as a creative art form along with mail art. Both of these explorations added to the visual and structural rhetoric that is now associated with contemporary zines. Inventive ways of binding pages and typographical playfulness also transferred to the zine. These characteristics, coupled with readily accessible photocopiers in the late 1970s led to an explosion of zines.
See a timeline (this link opens a new browser window)
For an expanded historical timeline associated with zines download a PowerPoint presentation here