National Turnout Rates Graph
National general election voting-eligible population turnout rates for presidential and midterm elections are from two sources. Modern Turnout rates from 1948-present are calculated by Michael McDonald (as they are published on this website). Pre-1948 turnout rates were provided to me by Walter Dean Burnham, to whom I and many others are deeply indebted for his historical work.
For further information see data and documentation for this chart.