Mattachine Society of New York. "Homosexuals Are Different . . ." Poster, 1960s. NYPL, Manuscripts and Archives Division, Mattachine Society of New York Records.
Political memorabilia are a particularly rich resource for understanding the transformation of American politics across the 19th and 20th centuries, documenting expanding avenues of activism and electioneering, shifting political party platforms, and the culture of nominating conventions. Beyond their immediate goal of promoting political candidates and their parties, these physical objects also served to simplify complex personalities and issues, and generate and maintain emotional bonds between candidates and constituencies. Through their texts, imagery, design and materials, campaign memorabilia offer direct access to lives of everyday people and their concerns.
The Bread and Roses Strike of 1912 exhibit from the Digital Public Library of America is divided into six themed primary source driven collections with exploratory text and multiple pages.
The links contained here from the DPLA are for guided exhibits on 20th century activism in the US. Most exhibit sections have 4-5 primary source images/documents.
This Land Is Your Land: Parks and Public Spaces is an exhibit of the Digital Public Library of America. Each themed resource collection is linked below by title.