Probably the most recognizable symbol associated symbol with the traditional outhouse building is the familiar crescent moon carved into the privy door. Actually, the symbol is an ancient one, and was a sign for womanhood in colonial days and on the frontier. It's male counterpart, Sol, was either a star or a sun burst design also on the door. Since most male outhouses fell into disrepair rather quickly they seldom survived; while the female ones were better maintained, and were eventually used by both sexes. Although you can find outhouses still standing with the crescent moon, the original meaning for gender identification was lost by the later nineteenth century in most areas of the country.
Carved crescent moons and stars on outhouse doors was introduced in early 19th century America. Typically, the moon and the star together represented a unisex outhouse, while the moon alone represented a women's outhouse. A star alone represented a men's outhouse.