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:
28 September 1958 (French Constitution)

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