The Thirty-Sixth Parallel South is a circle of latitude that is 36 degrees south of the Earth's equatorial plane. It runs through several countries, including Australia, New Zealand, and parts of South America. This parallel is significant in geography and climate studies, as it often marks the boundary between different climate zones. In the United States, the Thirty-Sixth Parallel South is notable for its historical context, particularly in relation to the Missouri Compromise of 1820. This agreement attempted to balance the number of free and slave states, using the parallel as a dividing line for future states in the western territories.