Complex sentence: Having researched Hamilton for more than forty years, she is regarded as one of the leading experts on Alexander Hamilton and has published several books as well as numerous articles and op-eds in newspapers and academic journals referencing this notable Founding Father.
Split into simpler sentences: Having researched Hamilton for more than forty years, she is regarded as one of the leading experts on Alexander Hamilton. Freeman has published several books as well as numerous articles and op-eds in newspapers and academic journals referencing this notable Founding Father.