The Library's main collection of American newspapers of the 1960s and 1970s is ProQuest Historical Newspapers:
You can also search ProQuest's files of African American newspapers separately, should that be useful in your research:
For more help finding newspapers, please consult our guide to Finding Newspapers:
Serial publications of the non-mainstream media are often referred to as the “alternative press” or “underground press," which include newspapers, magazines, newsletters, and other types of serial publications. These periodicals tend to be written from an acknowledged political perspective–for example, antiwar–and they often promote a specific agenda. They might, however, report on news that is of interest to a specific community—often a marginalized one—without endorsing any defined ideology. Examples of these might be African American newspapers, gay and lesbian magazines, military newspapers, or publications of immigrant groups. One scholar has defined them as "periodicals aimed at certain minority or dissident groups and usually distributed through irregular channels."1
1. Mary Allcorn, The Underground Newspaper Collection of the University of Missouri Libraries (Ann Arbor: UMI, 1992), i.