In contrast to the patriotic, colorful war propaganda posters of the first half of the 20th century, the 1960s and 70s gave rise to another type of political advertisement -- the simply drawn, sometimes sobering protest poster. Decorating the bulletin boards of college campuses, these posters served as rallying cries for peace, defamations of Nixon and the federal government, and tributes to the martyrs of the civil rights movement.

Here's a selection of 25 posters from 1969 to 1974, compiled from "The Art of Protest" collection at the San José State University Library.