US States without the death penalty

Alaska(Abolished at statehood, 1957)
Hawaii(Abolished at statehood, 1957)
Iowa(Abolished 1872; Reinstated 1878; Abolished again 1965)
Maine(Abolished 1887)
Massachusetts(De Facto abolished, 1947; De Jure abolished 1984)
Michigan(De Facto Abolished at statehood, 1837; De Jure Abolished 1846)
Minnesota(Abolished 1911)
North Dakota(De Facto Abolished 1930; De Jure Abolished 1973)
Rhode Island(De Facto Abolished 1930; De Jure Abolished 1984)
Vermont(De Facto Abolished 1964; De Jure Abolished 1987)
West Virginia(Abolished 1965)
Wisconsin(Abolished 1853)
*District of Columbia(Abolished 1972 by the Supreme court, never reinstated locally)

Also, several states have not executed anyone since the death penalty was reinstated by the supreme court in 1976. They are:

*OK, so DC isn't really a state. So sue me.

Death penalty	So Sue Me	New Mexico law against cohabitation	research is fun
de jure	Gregg v. Georgia	Iowa	Texas
Randall Dale Adams	Furman v. Georgia	Michael Schumacher	Kobold
South Dakota	Capital punishment	New Hampshire	Hawaii
District of Columbia	Maine	de facto	Kansas
Connecticut	New England	Massachusetts	Alaska