The air defense of America began with this call.
( ( ( The ( air defense ) ) ( of America ) ) ( ( began ( with ( this call ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN air) (NN defense)) (PP (IN of) (NP (NNP America)))) (VP (VBD began) (PP (IN with) (NP (DT this) (NN call)))) (. .)))
This call began the air defense of America.
( ( This call ) ( ( began ( ( the ( air defense ) ) ( of America ) ) ) . ) )
(ROOT (S (NP (DT This) (NN call)) (VP (VBD began) (NP (NP (DT the) (NN air) (NN defense)) (PP (IN of) (NP (NNP America))))) (. .)))