That would probably be the Schmidt Rubin bayonet - yes, Dick, it's Swiss.  Any serial number would be the first giveaway and the ratio of the pummel (?) to wood of the handle is another.  Also, the front of the pommel is at a slight angle to the wood - not at 90 degrees like the Krag.  Most of the first year of the Krags (1894) were struck a little on the light and small side, but the US was usually pretty strong.  The scabbards of the Krags were significantly different than the Swiss.  As Dick said, that will be a giveaway if there is a scabbard present.