Mouse over or tap a bar in the chart to see the figures for that year.
A botched lethal injection in Arizona in July followed a similar episode in Oklahoma this spring. The incidents have once again thrown the prevailing method of execution in the United States into turmoil.
How states have executed prisoners has changed over time. More than half of the 15,746 executions in U.S. history have been by hanging. Today, lethal injection has replaced electrocution as the dominant method of capital punishment in the United States. Lethal injection has failed to quickly kill a convict before this year too. (There were no executions from 1967 to 1977. They resumed following a Supreme Court ruling.)
—Emily Maltby and Lon Tweeten contributed reporting to this story. The source code for this project is available on Time’s GitHub page. This post was updated on December 16, 2015 to reflect most recent figures.