According to a November 6, 2016 Shutterbug article:

The famous George Eastman Museum has created a new, public portal where you can view over 250,000 images and other objects from their vast collections. The database is searchable by artist, collection, classification and date, and includes a wealth of photography, cinema, and technology related to imaging.

…

The 250,000 objects currently on the site are but a mere fraction of the museum’s collections of several million objects, but additional holdings are being added to the portal weekly.

It’s certainly an impressive undertaking. I briefly browsed through it and there’s a lot to see. Unfortunately they seem have started off with the image metadata, to which they are gradually adding images. I imagine it’s faster to add the metadata than it is to scan all the images. So the end result is that many of the entries indicate that the image is “not available”. For example I searched for Ansel Adams and got 18 pages of results. On the first page there were 24 entries. 18 of them indicated that the image was not available. I’m sure that over time these gaps will be filled.

It’s potentially a great resource.