REMOVE

1. automobiles
2. bridges (built works)
3. fences
4. barns

WHAT

1. Chevrolet Corvair automob … (1)
2. Visual Works (hierarchy n … (1)

More 

WHERE

1. Carroll County, Maryland (1)
2. Maryland Route 407 (state … (1)
3. Sam's Creek Road, Carroll … (1)
4. Westminster, Maryland (1)

Less

WHO

1. Still, Clyfford (1)
2. Still, Patricia (1)

WHEN

1. 1970 (1)
2. circa 1970 August (1)