Big old plain brown crock straight out of an estate in northern Illinois. I don't see a marking, but it could easily be out of any one of a number of potteries making utility wares during the late 19th and early 20th centuries.
We like the shape, and the weighty heft of this one... it's 7 1/2" in diameter, stands about 8 3/4" tall. There's no lid (often times the lid has been nothing more than a piece of wood, or an old plate pressed into service for many years!)
The crock is crack free and water tight, even though it looks a little rough. Makes a lovely large preserves jar for your pickles etc..