ID needed on this buckle

[Ripcon]

I found this brass buckle in a Vicksburg campaign site area. I put a penny beside it for scale (the wife misplaced my measuring tape!).
I've posted front and back photos. Any ideas if this was a belt buckle or an equestrian buckle or some other buckle device? Thanks for any assistance.

 

[Dfxcobb]

looks like a sash buckle to me.

 

[A2coins]

Nice relic looks like a belt guide

 

[Ripcon]

Thanks!

 

[Ripcon]

I just saw a picture and discovered that this buckle is actually a WWI Mackinaw coat buckle.

 

[A2coins]

There you go awesome ID and find congrats

 

[devldog]

Nice find and relic. Congrat's.

 

[Hawks88]

Nice Find. Congrats

 

[ARC]

Slide adjuster.

 

[Ripcon]

Thanks for everyone's assistance!