We develop a rich general equilibrium overlapping generations model to quantify the role of trends in labor income inequality, longevity, capital income inequality and taxation on the changes in the distribution of wealth in the U.S. Unlike earlier research, which emphasizes the role of labor income and capital income shocks, we show that the key drivers of changes in the wealth distribution lie in the demographic processes. We decompose changes in wealth inequality to within (birth) cohort and between (birth) cohort components and show that the between component, driven predominantly by increased life span after retirement is a key driver of increased wealth inequality in the US. Our setup permits counterfactual simulations with progressive income and wealth taxes and shows that the trend in longevity cannot be feasibly attenuated with taxation.