Beautiful long hair was considered a woman's crowning glory in the 1800's and this is very evident in today's tintype which features two women proudly showing of their very very long, dark-colored hair. This photo seems to have been well thought out as each woman is wearing a white dress to best accentuate her hair. I like how the photographer has posed these women, one sitting and one standing, each with their hair over their shoulder down the front.
It appears that these women are related from their facial features, and I believe they were most likely mother and daughter. I had real trouble dating this photo. My feeling is that it was probably taken late 1870's to early 1880's, however I could be wrong.