A lot of crescendos of this type are made using the dominant chord ( E in the key of A for example ) maybe followed by the dominant 7th ( E7 ) over a number of bars (4 or 8 bars maybe ) then after the build revert to the tonic or root ( A ).
e.g.

| E / / / | E / / / | E 7 / / / | E 7 / / / | A