UCLA just launched a profoundly awesome historical archive of news photographs from the Los Angeles Times and the Los Angeles Daily News.
Of the 5,124 images in this database, the oldest is from 1914. One fun way to search is typing in a year, say "1921" or "1928," and browse by date.
I spent about 4 hours straight on Friday poring through by keyword, related themes, and date, and found the two images you see in this post.
Photo above: the first generation of Trekkies, a bunch of Caltech students, protest the rumored cancellation of Star Trek at NBC's studios. I love how that one guy's sign says, "IT IS TOTALLY ILLOGICAL TO CANCEL STAR TREK."
These, dear BoingBoing reader, are our ancestors.
Photo at bottom: "Research assistant in automobile simulator during drug and alcohol experiment at Southern California Research Institute, 1977."
Try keyword-searching by "prohibition", or "zoot suit riot," for incredible images from specific political eras. For instance, "draft" will yield images related to Vietnam, but also protests from 1948.
Here's a list of more photos I found and was fascinated by, in no particular order:
Reader comment: Ole Squirrelly Eyes says,
I found the gubner! Link to Arnold Schwarzenegger, in 1975.