Although we associate trench warfare with World War I, trenches were characteristic also of the Civil War.
( ( Although ( we ( ( associate ( trench warfare ) ) ( with ( World ( War I ) ) ) ) ) ) ( , ( trenches ( ( ( were characteristic ) ( also ( of ( the ( Civil War ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (PRP we)) (VP (VBP associate) (NP (NN trench) (NN warfare)) (PP (IN with) (NP (NNP World) (NNP War) (PRP I)))))) (, ,) (NP (NNS trenches)) (VP (VBD were) (ADJP (JJ characteristic)) (PP (ADVP (RB also)) (IN of) (NP (DT the) (NNP Civil) (NNP War)))) (. .)))
There were no trenches in the Civil War, only in World War I.
( There ( ( ( were ( ( no trenches ) ( in ( the ( Civil War ) ) ) ) ) , ) ( only ( in ( World ( War I. ) ) ) ) ) )
(ROOT (S (NP (EX There)) (VP (VBD were) (NP (NP (DT no) (NNS trenches)) (PP (IN in) (NP (DT the) (NNP Civil) (NNP War)))) (, ,) (ADVP (RB only) (PP (IN in) (NP (NNP World) (NNP War) (NNP I.)))))))