Complex sentence: He was also the main person who negotiated new financing to the LDS Church in New York at that time that kept the church going until Lorenzo Snow's late-1890s call for tithing got the church in a better financial situation.
Split into simpler sentences: He was also the main person to negotiate new financing to the LDS Church in New York at the time. His efforts kept the church going until Lorenzo Snow's late-1890s call for tithing got the church a better financial situation.