The temperate deciduous forest of eastern North America, a vital provider of environmental, economic, and societal services, faces a crucial challenge in understanding its response to climate changes. High historical precipitation levels, combined with limited studies on its vulnerability to drought, have left this ecosystem's sensitivity to ongoing and future climate shifts largely uncharted. Thus, a better understanding of the physiological sensitivity of eastern temperate tree species to hydrologic variation and wildfire is needed to anticipate how forest composition will respond to projected climate changes in eastern North America in the coming decades. Paleorecords offer a unique opportunity to delve into past forest dynamics and species' drought sensitivity beyond instrumental records. Abrupt declines in species like eastern hemlock and American beech, known for their preference for mesic conditions and intolerance to water stress, are attributed to drought-induced dieback. A holistic approach, encompassing an examination of stable carbon isotopes (δ13C values) in fossil pollen grains, helps assess changes in water use efficiency and the influence of warming and drying on these tree species. This study seeks to uncover the ecosystem's responses to climate fluctuations, offering invaluable insights into the past and future. A better understanding of the response of eastern forests to past changes in climate and fire can provide context for projecting future vulnerabilities and developing managements and conservation strategies to maintain healthy forests during the Anthropocene.