Sauvagie=Savoy?

Cornelius Vanderbilt

His mother's side goes back to the surname Lum. Check out what it means

Lum" is English in origin. A habitational name from places in Lancashire and West Yorkshire called Lumb, both apparently originally named with Old English lum(m), meaning ‘pool’. In some instances, the name may be topographical for someone who lived by a pool, from the Middle English term lum(m).

The "Lum" surname was first found among families in Northumberland, where they were Lords of the manor of West Denton. The family motto translates to, "By valour and faith." In the United States, descendants include President Ulysses S. Grant.

His father's wife's line goes back to Sauvagie.