Presidential turnout rose steadily from 1920 to 1960

Evidence

From 1920, when women got the vote, through 1960, turnout in presidential elections had risen at the rate of 1.6 percent every four years, so on a simple straight-line projection it seemed reasonable, as a leading political scientist later observed, to expect turnout to be nearly 70 percent and rising on the nation’s two hundredth birthday in 1976. — Robert D. Putnam, Bowling Alone The Collapse and Revival…, 27