I found a bunch of these on my property. I think there could be a whole bunch in a low spot. This company, I found out, made pavers and bricks from 1897 - 1929. These are old road pavers.
They're cool too find, unless you digging fence post holes... Then they suck... my back yard is full of them since our road used to be cobble stone....
I have around a dozen bricks from the Bessemer Block Co., out of Youngstown, Ohio. These were used for roads around town back in the day. When they tore the old brick roads up to change over TOO asphalt I grabbed a few.