Complex sentence: It was not unusual for millionaires of the day to arrange marriages; so James Mink offered a substantial dowry for his daughter's hand; some research report about $10,000, which would have bought a city block in 1852 !
Split into simpler sentences: It was not unusual for millionaires of the day to arrange marriages, so James Mink offered a substantial dowry for his daughter's hand. Some research reports about $10,000, which would have bought a city block in 1852!