1st Inf SSI Date?

[ks kid]

I'm trying to learn about this patch. I think it's US made, WW II era, but there doesn't seem to be nearly as much info out there as I found for my 101st Abn patch. Any help with date & origin would be appreciated. 

[Blacksmith]

Overlocked edge and “tail” = circa 1980s

[atb]

70s, 80s, 90s, and on into the 2000s.