Whiteman had four wives and five children. His up and down swings made him a hard man to live with. His fourth wife stayed with him for 37 years, until his death. It seems it took a lot of practice before he could become one of the "family people."
He began his professional music career playing viola with the Denver and San Francisco symphony orchestras, but found that jazz would double his pay.
He brought more good musicians and vocalists into the light than any other band leader and paid them well. This is his real legacy.
He was first to hire a full-time female vocalist, Mildred Bailey.

He played the jazz most people wanted to hear and made millions. He was not a creative jazz musician, but took the rough edges off jazz and the world listened. Symphonic music remained part of his jazz music; he said, in a NY Times interview, "You'll never learn to bounce in jazz if you don't know your Bach and Beethoven."
He was a strong believer in careful arrangements, thus was disliked by those who preferred improvisization.

He became so popular that at one time he had almost 50 bands playing under his name.
Most of the above from musicianguide.com