After a 10-year moratorium, the death penalty became a part of the US criminal justice system again in 1977 when a firing squad killed the murderer Gary Gilmore.
Since then, the US has executed 1,400 criminals, as shown in the graphic and map below. Some states have contributed to that total more than others.
Reuters
Of the states that haven't abolished the death penalty, Texas has carried out the most executions with 520 since 1977. As of October 2013, one county in Texas, Harris County, had executed more people than any other in America. More than half of America's executions since 1977 come from 2% of its counties.
Oklahoma and Virginia follow closely behind Texas with 112 and 110 executions, respectively. Those three states are the only that break 100.
Of the 1,400 people who have been executed, the vast majority, 87.5%, died by lethal injection. Now that the US faces a shortage of pentobarbital, the drug used in lethal injections, some states have considered alternative means like firing squads.
After its reinstatement in 1977, the death penalty slowly grew as a punishment for crimes until it peaked in 1999 with 98 executions. Since then, capital punishment has started a slow, albeit uneven, decline.
In 2014, new death sentences reached their lowest level in the modern era of the death penalty, according to the Death Penalty Information Center. Last year, however, 35 people were put to death, on par with numbers in the early- to-mid '90s.