Google has taken images from the seminal magazine LIFE, and created Google Life Photo Archive. I have a copy of LIFE magazine from 1965 featuring the first space walk, it took me seconds to find the cover.
The photos reflect the high quality of the publication in their composition. There are millions of photos in the archives and most of them have not appeared in the magazine. This would be useful in a history class to view the world through the eyes of middle class America.
If you specify a year eg "1965 source:life" in Google Images you firstly see all the covers from that year and then pictures taken in that year. Just note the images are copyrighted.