No, I am not assuming anything. If I don't have at least one source to say American Game is a breed created or developed in the United States and when, then how can I put the breed on the list?
You'll have to track down some actual gamecock people and ask. You're asking about a fowl that was used for fighting, it's not a popular topic around here. You don't seem to understand that, or that once that happened, records and histories about cockfighting in the US disappeared or don't exist. Most of it is verbal history. That's the point I was trying to get across to you.