Unless there is a burned in maker's stamp on the chair, no one can tell you who made them. And without a closer look it's almost impossible to say when.
Is the rush seat natural rush? twisted paper or plastic? Are there tool marks on the turnings? any wear on the rungs or the bottom?
They could possibly be 100 years old...or brand new.

Here is a link that might be useful: ladderback chairs

My hunch tends to be it's newer. Or else newly refinished and a new seat done. I love ladderback chairs and have an old one I got at auction. The wood shows wear at the base of each leg and the top of the front two legs. Also the tops of the front legs of mine have very small slits in the wood. Kind of like spokes in a wheel from the center of the leg outward. I couldn't sand that part out if I wanted to, it's small but runs too deep to sand. That part could be from storage in extreme temps or something, but it doesn't bother me, I like the character. Looking past the finish to the wood itself, does yours have any signs of age/wear/use that we can't see in the photo?