Sixth-plate daguerreotype in a full case behind a double mat. Based on ID'd photos picked up with this image, she was probably a member of the Slocum / Pitkin family of New York State and Pennsylvania.
Dag is unsealed with tarnish ring but appears to be in excellent condition. I do not see any corrosion, swipes or scratches. The particles on the underside of the glass should clean up easily if you decide to do so.
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