I apparently missed this back in November of 2008 but I just came across this archive of LIFE’s photographs at Google Images.
It dates back to the 1750’s and most of them have never been printed or seen anywhere else.
Only a very small percentage of these images have ever been published. The rest have been sitting in dusty archives in the form of negatives, slides, glass plates, etchings, and prints. We’re digitizing them so that everyone can easily experience these fascinating moments in time. Today about 20 percent of the collection is online; during the next few months, we will be adding the entire LIFE archive — about 10 million photos.
That was posted by Google back on 18 Nov 2008 – I am sure the collection is complete by now.
Amazing what you come across sometimes on the Internet.