United Kingdom
unwritten; partly statutes, partly common law and
practice

United States
17 September 1787, effective 4 March 1789

Uruguay
27 November 1966, effective February 1967; suspended 27 June
1973, new constitution rejected by referendum 30 November 1980; two
constitutional reforms approved by plebiscite 26 November 1989 and 7
January 1997

Uzbekistan
new constitution adopted 8 December 1992

Vanuatu
30 July 1980

Venezuela
30 December 1999

Vietnam
15 April 1992

Virgin Islands
Revised Organic Act of 22 July 1954

Wallis and Futuna
4 October 1958 (French Constitution)

Yemen
16 May 1991; amended 29 September 1994 and February 2001