REMOVE

1. trees
2. portraits
3. sky
4. farms
5. hats
6. fields (land)

WHAT

1. Visual Works (hierarchy n … (2)
2. automobiles (2)
3. black-and-white film (2)
4. bushes (2)
5. exterior views (2)

More 

WHERE

1. New Windsor, Maryland (2)

WHEN

1. 1966 (1)
2. 1967 (1)
3. after 1966 (1)