Gary Gilmore was the first man executed in the United States after a ten year hiatus. The lower courts had already halted executions before the Supreme Court found in 1972 in Furman v. Georgia that state laws were unlawful under the cruel and unusual punishment clause of the US Constitution due to vast discrepancies in the structure and application of the state laws. In 1976, in Gregg v. Georgia the Court refused to strike down a new state law that was passed and which avoided the objections stated in the Furman case. Even so, the states did not proceed to execute anyone until Gilmore requested to be executed by firing squad. His wish was granted on 17 January 1977. Four of the five rifles were loaded with live ammo, one was blank. He was pronounced dead immediately. More than seven hundred executions took place nationwide since then. Gilmore's final words are reported to be: "Let's do it."

See:
http://www.biography.com/people/gary-gilmore-11730320
http://en.wikipedia.org/wiki/Gary_Gilmore
http://www.crimelibrary.com/notorious_murders/mass/gilmore/begin_7.html