Execution by electrocution (usually referred to as the electric chair or simply the chair after its method of implementation) is an execution method originating in the United States in which the person being put to death is strapped to a specially built wooden chair and electrocuted through electrodes placed on the body. This execution method has been used only in the United States and, for a period of several decades, in the Philippines (its first use there in 1924, last in 1976). The electric chair has become a symbol of the death penalty; however, its use is in decline.
Historically, once the person was attached to the chair, various cycles (differing in voltage and duration) of alternating would be passed through that person's body, in order to fatally damage the internal organs (including the brain). The first jolt of electrical current was designed to cause immediate unconsciousness and brain death; the second one was designed to cause fatal damage to the vital organs. Death was frequently caused by electrical overstimulation of the heart.
The electric chair was first used in 1890. It was used by more than 25 states throughout the 20th century, acquiring nicknames such as Sizzlin' Sally, Old Smokey, Old Sparky, Yellow Mama, and Gruesome Gertie. In the late 20th century, the electric chair was removed as a form of execution in many U.S. states, and its use in the 21st century is very infrequent.
Electrocution is currently an optional form of execution in the U.S. States of Alabama, Florida, South Carolina and Virginia, though they allow the prisoner to choose lethal injection as an alternative method. In the states of Kentucky and Tennessee, the electric chair has been retired except for those whose capital crimes were committed prior to legislated dates in 1998 (Kentucky March 31, 1998, Tennessee December 31, 1998) and who choose electrocution. In both states, inmates who do not choose electrocution or inmates who committed their crimes after the designated date are put to death by lethal injection. The electric chair is an alternate form of execution approved for potential use in Illinois and Oklahoma if other forms of execution are found unconstitutional in the state at the time of execution.
On February 8, 2008, the Nebraska Supreme Court determined that execution via the electric chair was a "cruel and unusual punishment" under the State's constitution. This brought executions of this type to an end in Nebraska, the only remaining state to retain it as its sole method of execution.
(taken from http://en.wikipedia.org/wiki/Electric_chair)
The use of the electric chair has been classified as "cruel and unusual punishment" due to various instances where the subjects had not been killed instantly at the first shock, but had to then be subjected to many shocks after that before they were killed. This was somewhat addressed by having a uniform amount of shock to be sent through the subject, but several instances have still surfaced where the prisoner did not die immediately.
There have been incidents of a person's head on fire; or of a burnt electrical transformer. In 1946, the electric chair failed to execute Willie Francis, who reportedly shrieked "take it off! Let me breathe!" as he was being executed. It turned out that the portable electric chair had been improperly set up by an intoxicated trustie. A case was brought before the U.S. Supreme Court (Francis v. Resweber), with lawyers for the condemned arguing that although Francis did not die, he had, in fact, been executed. The argument was rejected on the basis that re-execution did not violate the double jeopardy clause of the 5th Amendment of the US Constitution, and Francis was returned to the electric chair and successfully executed in 1947.
(http://en.wikipedia.org/wiki/Electric_chair)
As of 2008, the only places in the world which still reserve the electric chair as an option for execution are the U.S. states of Alabama, Florida, South Carolina, Kentucky, Tennesse and Virginia. (Oklahoma, Arkansas and Illinois laws provide for its use should lethal injection ever be held to be unconstitutional). Inmates in the other states must select either it or lethal injection