FN FMCCFX HH ACESDGHL

[supermouse]

Disappointed by the meagre offerings for puzzle solving on the Sherlock website, I've spent a quiet afternoon putting together the following:

DWFT FG H LJXDUERA OAT IBCQ H IGKJCFMH HIB FNCUJC DKCGBRCWG KJB HACKDR JWB XIPIMJ CIP H LDUB UBJFX HUGU F GALF JEVBUDR H ZAUA FJOHLC TEX H OAEIABMB JDQC IJ BBBD QDG DDDU IZAOEAGY DRAK H VAU JBCTCCD JIMES H BFX IN CQB SF YG AERG KA OGXI JAYAOG VIX BPA SD LAND FIMERIL IB CJAEIU

Just to add to the joy, there may well be transcription errors. I've tried my best to make sure there aren't.

Questions:

Where's the quote taken from?
What is the cipher used?
Is there a website that lets me do this automatically?

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