The top marginal tax rate under President Eisenhower in the 1950's was 91.6% as per the link above. It was an era of balanced or surplus budgets, low unemployment and low interest rates. Clinton raised taxes in 1994 and presided over 6 years of strong economic growth after that. The correlation between low rates of taxation and a strong economy which is uncritically parroted by some doesn't always bear empirical scrutiny.