The Thirty-Sixth Parallel is a circle of latitude that is 36 degrees north of the Earth's equatorial plane. It runs across several countries, including the United States, where it passes through states like California, Arizona, and New Mexico. This parallel is significant in geography and has historical importance, particularly in the context of the U.S. Civil War and Westward Expansion. In addition to its geographical relevance, the Thirty-Sixth Parallel has been used as a reference point in various political and military contexts. For example, it served as a dividing line during the Korean War, influencing the establishment of the Korean Demilitarized Zone.