Button ID help needed.

[NJ Marty]

Got out this weekend and hunted some woods in Staten Island and got this neat button. I can only make out ' OF THE REPUBLIC'. Any help with the time frame and ID would be appreciated.
Marty

 

[umrgolf]

Grand Army of the Republic (Civil War Veterans-Union)

 

[gregd573]

GAR button.....I think it is Grand Army of the Republic.....should be able to pull up info on the internet and a good find

gregd

 

[RELICDUDE07]

Don't think its a button, made to stay in leather from the back!

 

[kuger]

Yea,looks like a Rivet

 

[vayank54]

It's a GAR (Grand Army of The Republic) collar stud. The GAR was made up of union civil war vets and I believe was started in the 1870's. Some of them have a field pack and a campfire on the back piece