Evidence suggests the hydrologic cycle is intensifying. Evapotranspiration is a significant variable in this cycle, but limited data and disputed study methods have left doubts regarding its historical trends. We estimated evapotranspiration trends over the 20th century by analyzing the water budget of 9 large hydrological units in the Eastern United States. By comparing hydrologic data and satellite based vegetation observations, we determined that increasing precipitation has stimulated vegetation growth, which has led to an increase in evapotranspiration.