Complex sentence: By 1880, however, the recovery was well underway, with new builds in New York reaching 1871 volumes again, and the economic upturn made the construction of taller buildings an attractive financial option again, establishing many of the preconditions for the development of the skyscraper.
Split into simpler sentences: By 1880, however, the recovery was well underway, with new builds in New York, for example, finally reaching 1871 volumes again. With the economic upturn, constructing taller buildings became an attractive financial option once again, establishing many of the preconditions for the development of the skyscraper.