Any idea on the date of this button?

[tjb200]

 

[tjb200]

It was found on a farm house that was built in the 1870's

 

[pa-dirt_nc-sand]

Looks a little too big to be a 2 piece button and it looks to be iron vs typical brass. My guess is it is something other than a button.

 

[Gridwalker306]

Possibly a wheel from a toy car?

 

[Patriot Relics]

I'd say you have the iron back of an early 1900s civilian blazer button