Does anyone know what happened to Grant's sword?

Couple days ago I was watching either "Pickers" or "Pawn Stars" and a fellow presented what he said was Gen. Grant's (field)sword with no documentation. According to a historian the sword was the same type carried by Unio9n officers, French made. What caught my attention more than anything else, this sword was supposed to be handed down by one of Grant's slaves by the last name of Burwell. Anyone have a clue if Grant had a slave by that name? BTW the sword was not sold.

I have also looked at several website I cannot find a sword owned by Grant that looks like the field sword shown on TV. This sword appeared to have a curved blade.

Thanks,

GP