The State Constitutional Convention Clearinghouse

 

U.S. states where the people can use a state constitutional convention to bypass the legislature's gatekeeping power over constitutional amendment

Periodic Constitutional Convention Comparative Information

Date Amendment Enacted

  1. New Hampshire, 1792
  2. New York, 1846
  3. Michigan, 1850
  4. Maryland, 1851
  5. Ohio, 1851
  6. Iowa, 1857
  7. Oklahoma, 1907
  8. Missouri, 1921^
  9. Alaska, 1956^^
  10. Hawaii, 1959^^
  11. Connecticut, 1965
  12. Illinois, 1970
  13. Montana, 1972
  14. Rhode Island, 1973

First Implemented

  1. New Hampshire, 1800
  2. New York, 1866
  3. Michigan, 1866
  4. Iowa, 1870
  5. Ohio, 1871
  6. Maryland, 1887#
  7. Oklahoma, 1926
  8. Missouri, 1942
  9. Hawaii, 1966
  10. Alaska, 1970
  11. Rhode Island, 1984
  12. Connecticut, 1988
  13. Illinois, 1990
  14. Montana, 1990

Last Major Revision##

  1. Iowa, 1857
  2. Maryland, 1867
  3. Oklahoma, 1907
  4. Ohio, 1912
  5. New York, 1938
  6. Missouri, 1945
  7. Alaska, 1956
  8. Hawaii, 1959
  9. Michigan, 1960
  10. Connecticut, 1965
  11. Illinois, 1970
  12. Montana, 1972
  13. Rhode Island, 1973
  14. New Hampshire, 1980###

Period (Current)

  1. New Hampshire, every 10 years
  2. Iowa, every 10 years
  3. Alaska, every 10 years
  4. Hawaii, every 10 years
  5. Rhode Island, every 10 years
  6. Michigan, every 16 years
  7. New York, every 20 years
  8. Maryland, every 20 years
  9. Ohio, every 20 years
  10. Oklahoma, every 20 years**
  11. Missouri, every 20 years
  12. Connecticut, every 20 years
  13. Illinois, every 20 years
  14. Montana, every 20 years

Last Convention

  1. Iowa, 1857*
  2. Oklahoma, 1907**
  3. Missouri, 1945
  4. Ohio, 1951
  5. Alaska, 1956***
  6. Michigan, 1962****
  7. Connecticut, 1965*****
  8. Maryland, 1966*****
  9. New York, 1967*****
  10. Illinois, 1970
  11. Montana, 1972
  12. Hawaii, 1978
  13. New Hampshire, 1982
  14. Rhode Island, 1986

Last Referendum

  1. Oklahoma, 1970
  2. New York, 1997
  3. Missouri, 2002
  4. Hawaii, 2008
  5. Connecticut, 2008
  6. Illinois, 2008
  7. Michigan, 2010
  8. Maryland, 2010
  9. Iowa, 2010
  10. Montana, 2010
  11. New Hampshire, 2012
  12. Ohio, 2012
  13. Alaska, 2012
  14. Rhode Island, 2014

Next Referendum

  1. New York, 2017
  2. Hawaii, 2018
  3. Iowa, 2020
  4. Alaska, 2022
  5. Missouri, 2022
  6. New Hampshire, 2022
  7. Rhode Island, 2024
  8. Michigan, 2026
  9. Connecticut, 2028
  10. Hawaii, 2028
  11. Illinois, 2028
  12. Iowa, 2030
  13. Maryland, 2030
  14. Montana, 2030
  15. Alaska, 2032
  16. New Hampshire, 2032
  17. Ohio, 2032
  18. Oklahoma, **

Notes

^ Missouri’s periodic constitutional referendum was the only one created by a popular constitutional initiative.

^^ Alaskans ratified their Constitution in 1956, but it didn’t become effective until it was admitted into the Union in 1959.  Hawaiians ratified their Constitution shortly before being admitted into the Union in 1959.

# Maryland’s Office of Attorney General claims that this is the first use of the periodic referendum in Maryland history. However, referendums were arguably held under the periodic constitutional convention referendum (the original period was every 10 years)  in 1858, 1864, and 1867.   Maryland’s 1851 Constitution mandated that the referendum be placed on the ballot every ten years after the next U.S. Census.  The was no constitutional convention referendum in 1861.

## Last major revision of only the periodic constitutional convention section.  Other sections may have been revised more recently.

### Eliminated the town meeting referendum structure.

* In 1922, the people of Iowa voted to convene a state constitutional convention but the legislature refused to pass the enabling legislation to do so.

** Since 1970, Oklahoma’s legislature has refused to follow its Constitution with regard to this provision.  In 1994, it placed a referendum on the ballot to eliminate this requirement, but the people of Oklahoma defeated it.  Since 1990, many bills have been introduced to implement this part the Constitution but none has passed.

*** Alaska was a new state.  All new states must convene a state constitutional convention.

**** Michigan is the only state where its periodic constitutional convention referendum was substantially revised by a popular constitutional initiative.  This occurred in 1960 and paved the way for its 1961-2 constitutional convention.

***** A series of U.S. Supreme Court cases in the early 1960s mandating legislative reapportionment based on the principle of one-person, one-vote led to the wave of state constitutional conventions during this period.

Constitutional Initiative Comparative Information

Explicit Provision Added to Constitution Enumerating that the Constitutional Initiative can be Used to Call a Convention*

  1. Florida, 1968
  2. Montana, 1972
  3. South Dakota, 1972
  4. North Dakota, 1972

Implicit Constitutional Initiative Used to Call a Convention

  1. Michigan, 1961

Explicit Constitutional Initiative Used to Call a Convention

None.

Constitutional Initiative Used to Modify a Constitutional Convention Provision

  1. Michigan, 1961

Explicit Constitutional Initiative Used to Call a Convention

  1. Missouri, 1921

Notes

* All were added at a state constitutional convention.