The Kammer & Reinhardt doll company was founded in 1885 by the sculptor Ernst Kammer and the salesman Franz Reinhardt in Waltershausen, Thuringia, Germany. Kammer & Reinhardt designed their dolls body and bisque heads, but most of the heads were manufactured by the German company Simon & Halbig (which is why many dolls bare both companies mark on the dolls neck) as they did not have their own porcelain factory. Kammer & Reinhardt also purchased bisque doll heads from the porcelain factories of Kling, Quendt & Schuetzmeister. In 1902 they purchased the Heinrich Handwerck doll company, when it's founder passed away. By 1920 they acquired the Simon & Halbig company as well.
From 1886 to 1909 kammer & Reinhardt made only dolly faced dolls with a bisque head on a composition ball jointed body or kid, many with an open mouth with teeth. After 1909 K&R made many types of German dolls, both bisque or composition heads and even cloth costume dolls with wired bodies dressed in various professions. However they are probably best known for their character baby and child dolls.
What's it worth? Take a look at this Kammer Reinhardt price guide: sold listings for a value indication.