Complex sentence: Significant parts of the construction were completed by 1796, including the stretch up to Bury in October, and in the following year with the completion of the Bolton arm much of the canal opened for business.
Split into simpler sentences: Significant parts of the canal were completed by 1796, including the stretch up to Bury in October of that year. With the completion of the Bolton arm in the following year, much of the canal opened for business.