US presidential election voter turnout never dropped below 69.8% between 1840 and 1900, with a peak of 82.6% in 1876. Before and after, participation has dipped as low as 50%. Do we know what caused election participation to spike in the 19th century?

by RusticBohemian
thefourthmaninaboat

There's always more that can be said, but /u/Georgy_K_Zhukov has discussed election turnout in the late 19th Century here.