IRS - Personal Exemptions and Individual Income Tax Rates, 1913–2002
irs.gov/pub/irs-soi/...
Key history: top marginal rate reached 92% during the Korean War, remained 91% for several years, was 70% from 1965–1980, then fell to 50% (1982), 38.5% (1987), and 28% (1988).