The Bizarre Phenomenon of Mass Photography
io9.com/the-bizarre-phenomenon-of-mass-photography-477602933
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
In the early twentieth century, photographers fell in love with "mass photographs," or pictures where thousands of people create one unified image. Often, at this time in history, the themes were patriotic and the participants were soldiers. Here are some of the most astounding.