George Eastman House has a growing list of a lot of easily accessed photographs by people like

Atget

many unidentified photgraphers,

Lewis Hine,

Joe Rosenthal's Iwo Jima,

and other images of historical significance,

or just plain marvels like this combination birdcage aquarium plant stand

and discoveries like Frederick Sommer

this photgraph is most amusing

whereas this is most disquieting