Complex sentence: There are no records as to the whereabouts or fate of Jimmy's father after 1906; it was not unusual in those days for single fathers to leave their children in the care of relatives and go "traveling", hopefully to find a new wife.
Split into simpler sentences: There are no records as to the whereabouts or fate of Jimmy's father after 1906. It was not unusual in those days for single fathers to leave their children in the care of relatives and go "traveling," hopefully to find a new wife.