Complex sentence: The most significant printing firm in the area was that founded by William Smith at Langley in 1820, this passed into the family of William Whiston and amalgamated with J & T Brocklehurst in 1929 to form BWA, Brocklehurst Whiston Amalgamated.
Split into simpler sentences: The most significant printing firm in the area was that founded by William Smith at Langley in 1820. This passed into the family of William Whiston and amalgamated with J & T Brocklehurst in 1929 to form BWA, Brocklehurst Whiston Amalgamated.