REMOVE

1. trucks
2. workers
3. plants
4. houses
5. buildings (structures)
6. automobiles

WHAT

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

More 

WHERE

1. Westminster, Maryland (1)

WHEN

1. 1961 (1)
2. after 1961 (1)