This is an old photograph of a horse with a curly mane. The photographer's stamp indicates it was taken in missouri, so it's entirely possible the horse pictured is an early bashkir curly, possible a missouri fox trotter with the curly gene. This horse is likely a minimal, judging from the coiling of the mane but lack of texture on the coat- OR it's simply shed out smooth as many moderate curlies do in shorts and short-sleeve weather.