REMOVE

1. buildings (structures)
2. rubbish
3. farms
4. clouds
5. bushes
6. 1961

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. black-and-white film (1)

More 

WHERE

1. Westminster, Maryland (1)

WHEN

1. after 1961 (1)