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)))) (. .)))
The call was made to ensure America's airspace would be safe.
( ( The call ) ( ( was ( made ( to ( ensure ( ( ( America 's ) airspace ) ( would ( be safe ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN call)) (VP (VBD was) (VP (VBN made) (S (VP (TO to) (VP (VB ensure) (SBAR (S (NP (NP (NNP America) (POS 's)) (NN airspace)) (VP (MD would) (VP (VB be) (ADJP (JJ safe))))))))))) (. .)))