Mattachine Society of New York. "Homosexuals Are Different . . ." Poster, 1960s. NYPL, Manuscripts and Archives Division, Mattachine Society of New York Records.
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.
Image above is from Getty Images (http://www.huffingtonpost.com/2013/10/01/government-shutdown-national-parks_n_4024123.html#slide=2929515 ; 2014)
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.