REMOVE

1. barriers
2. mountains
3. cranes (equipment)
4. rivers
5. black-and-white film
6. roads

WHAT

1. Visual Works (hierarchy n … (1)
2. banks (landforms) (1)
3. barns (1)
4. buildings (structures) (1)

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WHERE

1. Maryland (1)

WHEN

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