REMOVE

1. people, at work
2. albumen print
3. landscape, camp
4. Photographs
5. landscape, river

WHAT

1. albumen print (1)
2. landscape, camp (1)
3. landscape, river (1)
4. landscape, waterfalls (1)

More 

WHERE

1. North American; American (1)
2. US, ID (1)

WHO

1. George Eastman House (1)
2. O'Sullivan, Timothy H. (1)

WHEN

1. 1868 (1)
2. September, 1868 (1)