National Convention is the legislative body of the Fraternity in which undergraduate and alumni delegates, along with National Council, enact legislation and adopt positions on matters of national importance.

Leadership School is an annual national meeting held in approximately mid-August. In non-Convention years, Leadership School includes the Awards Luncheon and Annual Banquet.

In 1973, Triangle returned to a former practice of biennial instead of annual legislative meetings. In the odd-numbered years, Convention and Leadership School are combined in a sequence of alternate sessions.

December 9-11, 1909             Champaign, Illinois
February 3-4, 1911              West Lafayette, Indiana
February 2-3, 1912              Columbus, Ohio
February 7-8, 1913              Champaign, Illinois
February 27-28, 1914            Madison, Wisconsin
February 26-27, 1915            West Lafayette, Indiana
February 24-26, 1916            Columbus, Ohio
February 22-24, 1917            Champaign, Illinois
February 21-23, 1918            Madison, Wisconsin
March 6-8, 1919                 West Lafayette, Indiana
February 26-28, 1920            Columbus, Ohio
March 3-5, 1921                 Champaign, Illinois
May 4-6, 1922                   Madison, Wisconsin
May 3-5, 1923                   West Lafayette, Indiana
May 8-l0, 1924                  Lexington, Kentucky
April 30-May 2, 1925            Cincinnati, Ohio
April 22-24, 1926               Chicago, Illinois
April 28-30, 1927               Chicago, Illinois
April 26-28, 1928               Chicago, Illinois
April 25-27, 1929               Chicago, Illinois
May 1-3, 1930                   Chicago, Illinois
April 30-May 2, 1931            Chicago, Illinois
April 28-30, 1932               Urbana, Illinois
April 27-29, 1933               Chicago, Illinois
April 26-28, 1934               Chicago, Illinois
April 25-27, 1935               Chicago, Illinois
April 23-25, 1936               Columbus, Ohio
August 30-September 3, 1937     Rapid City, South Dakota
September 7-10, 1938            Chicago, Illinois
September 6-9, 1939             West Lafayette, Indiana
September 4-7, 1940             Minneapolis, Minnesota
September 3-6, 1941             Cincinnati, Ohio
October 25-27, 1946             Chicago, Illinois
September 3-5, 1947             Chicago, Illinois
September 2-5, 1948             Madison, Wisconsin
September 1-3, 1949             Louisville, Kentucky
August 30-September 2, 1950     Brainerd, Minnesota
September 6-8, 1951             Columbus, Ohio
September 10-13, 1952           Chicago, Illinois
August 31-September 4, 1953     Sylvan Lake, South Dakota
August 31-September 3, 1954     St. Louis, Missouri
August 30-September 2, 1955     University Park, Pennsylvania
August 28-31, 1957              Urbana, Illinois
September 2-5, 1959             Ithaca, New York
August 30-September 2, 1961     Milwaukee, Wisconsin
August 26-29, 1963              Excelsior Springs, Missouri
September 2-5, 1964             Champaign, Illinois
November 25-28, 1965            Cincinnati, Ohio
November 24-27, 1966            Chicago, Illinois
November 24-26, 1967            Minneapolis, Minnesota
November 29-December 1, 1968   Columbus, Ohio
August 27-30, 1969              Windsor, Ontario, Canada
September 2-5, 1970             Boulder, Colorado
September 2-4, 1971             Waukegan, Illinois
August 3-5, 1972                Waukegan, Illinois
August 9-11, 1973               Waukegan, Illinois
August 2, 1974                  Columbus, Ohio
August 14-16, 1975              Rolla, Missouri
August 14, 1976                 Pittsburgh, Pennsylvania
August 18-20, 1977              West Lafayette, Indiana
August 18-19, 1978              Lawrence, Kansas
August 16-18, 1979              Milwaukee, Wisconsin
August 15-16, 1980              Toledo, Ohio
August 13-15, 1981              Ann Arbor, Michigan
August 13-14, 1982              Champaign, Illinois
August 11-13, 1983              Cincinnati, Ohio
August 10-12, 1984              Ames, Iowa
August 15-17, 1985              Columbus, Ohio
August 14-16, 1986              St. Louis, Missouri
August 13-15, 1987              Milwaukee, Wisconsin
August 21-23, 1988              Lincoln, Nebraska
August 20-23, 1989              Ft. Collins, Colorado
August 12-14, 1990              Cincinnati, Ohio
August 11-14, 1991              Washington, D.C.
August 8-11, 1992               Rapid City, South Dakota
August 14-17, 1993              Indianapolis, Indiana
August 6-9, 1994                Madison, Wisconsin
August 5-8, 1995                Kansas City, Missouri
August 3-6, 1996                West Lafayette, Indiana
August 9-12, 1997               Minneapolis, Minnesota
August 1-4, 1998                Chicago, Illinois
August 7-10, 1999               Orlando, Florida
August 5-8, 2000                Ames, Iowa
August 3-6, 2001                St. Louis, Missouri
August 8-11, 2002               Brookston, Indiana
July 31-August 3, 2003          Louisville, Kentucky
July 29-August 1, 2004          Bloomington, Indiana
July 28-31, 2005                Lisle, Illinois
July 27-29, 2006                Champaign, Illinois
July 12-14, 2007                Indianapolis, Indiana