Basil Duke, who has appropriately been called the head and brains of John Morgan, is from Georgetown, Scott county, Kentucky, a few miles North of Lexington. He entered Yale College in 1841, and graduated in 1845. He is represented as having been a man of parts and of large heart.-The Daily Cleveland Herald, July 24, 1863
I had to look up "man of parts" because I had never heard the phrase before. It appears that a man of parts is one who is talented in multiple areas of life, including the seduction of women. In general, I think it means a man of general talent or abilities.