Complex sentence: The financing for rebuilding the downtown core came in large part from the infusion of investment from Dutch bankers; this investment was so deep that by 1896, one prominent Dutch mortgage company, the "Northwestern and Pacific Hypotheekbank" owned a quarter of the city.
Split into simpler sentences: The financing for rebuilding the downtown core came in large part from the infusion of investment from Dutch bankers. This investment was so deep that by 1896, one prominent Dutch mortgage company, the "Northwestern and Pacific Hypotheekbank" owned a quarter of the city.