Complex sentence: However, this left the door open for a private railway on the lands owned by Ward Jackson and his supporters, which they commenced to build in 1860 under the auspices of the "Upsall, Normanby and Osmesby Railway".
Split into simpler sentences: However, this left the door open for a private railway on the lands owned by Ward Jackson and his supporters. They began to construct it in 1860 under the auspices of the "Upsall, Normanby and Osmesby Railway".