REMOVE

1. rock
2. sky
3. machinery
4. farms
5. 1920
6. 1940

WHAT

1. black-and-white film (2)
2. cornstalk (2)
3. cranes (equipment) (2)
4. fields (land) (2)
5. freight cars (2)
6. hats (2)
7. hills (2)
8. landscapes (representatio … (2)
9. men (male humans) (2)
10. plants (2)
11. railroads (2)
12. rails (transit system ele … (2)
13. rubbish (2)
14. soil (2)
15. tools (2)
16. tractors (agricultural eq … (2)
17. trains (vehicle groupings … (2)
18. trees (2)
19. trucks (2)
20. utility poles (2)
21. Visual Works (hierarchy n … (2)
22. woods (plant communities) (2)
23. workers (2)

WHERE

1. New Windsor, Maryland (2)

WHO

1. Campbell, Sandra L. Still (2)
2. Clyfford Still; Still, Cl … (2)
3. Sandra L. Still Campbell; … (2)
4. Still, Clyfford (2)

More 

WHEN

1. 1969 (2)