This paper presents new homogeneous series on top shares of income and wages from 1913 to 1998 in the United States using individual tax returns data. The data show a U-shaped pattern in top income and wage shares over the century. The authors argue that the "technical change" view of inequality dynamics cannot fully account for the observed facts. The large shocks experienced by capital owners during the Great Depression and World War II seem to have had a permanent effect, with top capital incomes still lower in the late 1990s than before World War I. Progressive taxation, by reducing wealth accumulation at the top, may have prevented large fortunes from fully recovering from these shocks. The evidence on wage inequality shows that top wage shares were flat before WWII and dropped sharply during the war. Since the 1960s-1970s, top wage shares have started recovering and are now higher than before WWII. The authors emphasize the role of social norms as a potential explanation for the observed patterns. The paper also discusses the impact of fiscal manipulation and compares the findings to other countries.This paper presents new homogeneous series on top shares of income and wages from 1913 to 1998 in the United States using individual tax returns data. The data show a U-shaped pattern in top income and wage shares over the century. The authors argue that the "technical change" view of inequality dynamics cannot fully account for the observed facts. The large shocks experienced by capital owners during the Great Depression and World War II seem to have had a permanent effect, with top capital incomes still lower in the late 1990s than before World War I. Progressive taxation, by reducing wealth accumulation at the top, may have prevented large fortunes from fully recovering from these shocks. The evidence on wage inequality shows that top wage shares were flat before WWII and dropped sharply during the war. Since the 1960s-1970s, top wage shares have started recovering and are now higher than before WWII. The authors emphasize the role of social norms as a potential explanation for the observed patterns. The paper also discusses the impact of fiscal manipulation and compares the findings to other countries.