Theta Delta Chi (ΘΔΧ) is a social fraternity that was founded in 1847 at Union College, New York, United States. While nicknames differ from institution to institution, the most common nicknames for the fraternity are TDX, Thete, Theta Delt, and Thumpers. Theta Delta Chi brothers refer to their local organization as charges rather than using the common fraternity nomenclature of chapters.