Brown dwarfs are interesting and complex worlds that form a critical stepping stone along the path to imaging Earth-like planets. By examining their atmospheres in detail, we can better understand their thermal profiles, chemical composition, and cloud properties that are tightly coupled with their formation and evolution. Additionally, metallicity is an essential parameter for the characterization of brown dwarfs, as it plays a critical role in shaping the atmospheres we observe. The majority of known brown dwarfs are members of the thin disk in the Solar Neighborhood with solar metallicities. However, with the exceptional sensitivity of JWST, we are able to detect distant brown dwarfs in the thick disk and halo. These distant metal-poor systems enable us to study the early star formation and chemical evolution history of the Milky Way, and improve our understanding of metal-poor exoplanet analog atmospheres. In this poster, I will explain how my group uses atmospheric retrievals, a powerful inverse modeling technique, to examine the atmospheres of brown dwarfs. I will present results from brown dwarf retrievals using JWST spectra from the Arcana of Ancients Program to show how they have enhanced our understanding of substellar atmospheres and the retrieval approach.