April 29, 1864
Theta Xi was founded at Rensselaer Polytechnic Institute, Troy, New York, by Peter Henry Fox, Ralph Gooding Packard, Christopher Champlin Waite, George Bradford Brainerd, Samuel Buel, Jr., Henry Harrison Farnum, Thomas Cole Raymond and Nathaniel Henry Starbuck. The Fraternity was originally founded as an engineering fraternity, the first professional fraternity.
May 7, 1864
Edward H. Morrison, the first member of Theta Xi after the honored founders, was inititated eight days following the establishement of Alpha Chapter as Alpha 9.
April 21, 1865
The first Annual Convention was held at Troy, New York, under the auspices of Alpha Chapter.
September 28, 1867
Kappa Sigma Kappa was founded at the Virginia Military Institute, Lexington, Virginia, by David Gamble Murrell, John McClelland Tutwiler, Kenneth McDonald, and James Gunnell Hurst.
The Theta Xi Quarterly was first published by Charles W. Hoyt, Beta 166, in New Haven, Connecticut.
May 15, 1892
The first edition of the Catalogue or Membership List was compiled and published by Edwin F. Gillette, Alpha 100.
February 24, 1906
Centralized form of government was adopted, and the Grand Lodge was created as the central governing body. Major William H. Wiley, Alpha 11, was elected first President of the Grand Lodge.
February 20, 1915
The Life Membership Plan was created by the 51st Annual Convention (New York). William S. Mason, Beta 145, Hugh T. Wreaks, Gamma 69, and Henry A. Morss, Delta 59, enrolled as the first Life Members.
First office devoted exclusively to the business of the Fraternity was established in St. Louis, Missouri. On March 22, 1925, Harold P. Davison, lota 149, assumed office as the first full-time executive.
April 9, 1926
Theta Xi became a general college fraternity by a five-to-one vote of the membership, thus opening membership to men in all curricula.
The first edition of The Songs of Theta Xi was published.
The name of the official publication was changed from The Theta Xi Quarterly to The Unicorn of Theta Xi.
February 23, 1929
The Unicorn (endowment) Fund was created. A resolution to eliminate hazing was unanimously adopted by the active delegates to the 65th Annual Convention (San Francisco).
The first edition of the Theta Xi Pledge Manual was published.
September 5, 1931
The 67th Annual Convention (Columbus) adopted a definite expansion policy.
September 3, 1932
The 68th Annual Convention (Los Angeles) revised the coat of arms and adopted its shield as the new pledge button.
September 2, 1933
The 69th Annual Convention (Chicago) amended the constitution to provide for biennial instead of annual conventions.
September 15, 1935
Dr. Paul F. Opp directed the reorganization of Kappa Sigma Kappa at the University of Virginia by Frederick St. Paul Henstridge, Edwin Stone Laidlaw, and H. Rankin Miller.
August 30-September 2, 1939
The Diamond Anniversary Jubilee Convention was held in Troy, New York. The Memorial Seat was presented to Rensselaer Polytechnic Institute to commemorate the founding of Theta Xi.
"The Order of the Unicorn” was created, and the Founding of the Fraternity was dramatized. Plans were announced for the Regional Organization and the Theta Xi Foundation. Alpha Alpha Chapter won the first “Memorial Trophy” as the Outstanding Chapter.
June 15, 1940
The first regional conference, held in Lincoln, Nebraska under the direction of Earl T. Luff, Alpha Epsilon 3, was attended by representatives of Mu, Psi, Alpha Epsilon, and Alpha lota Chapters.
January 25, 1947
The Theta Xi Foundation was established.
August 27-30, 1947
The 83rd Anniversary Convention (Lincoln) created a Board of Trustees to handle and supervise the endowment funds.
December 28, 1948
Kappa Sigma Kappa held its first inter-chapter convention on the campus of Arkansas A.& M. College. Plans were made for annual conventions and publication of a magazine, The Iris, was authorized.
August 26-29, 1951
The “Purpose of Theta Xi” was adopted by the 87th Anniversary Convention (Pittsburgh).
August 30-September 2, 1953
The “Order of the Golden Star” was adopted by the 89th Anniversary Convention (Chicago).
March 8, 1954
Gifts and bequests to the Theta Xi Foundation became exempted from all taxes by the Internal Revenue Service.
August 20, 1962
A merger with Kappa Sigma Kappa was approved, and 21 chapters of that fraternity joined Theta Xi.
April 29, 1964
Commemorating the Centennial Anniversary of the founding of the Fraternity, the Memorial Headquarters was formally dedicated in St. Louis, Missouri.
August 28-31, 1966
The 102nd Anniversary Convention (Houston) established the position of Undergraduate Director on the Grand Lodge. Paul L. Stone, Alpha Beta 790, was the first undergraduate elected to this position.
August 22-25, 1968
The 104th Anniversary Convention (Philadelphia) amended the Constitution to provide that each member upon his initiation into the Fraternity received Life Membership in Theta Xi.
August 12, 1974
The 110th Anniversary Convention (Vail) adopted The National Multiple Sclerosis Society as the Fraternity’s National Service Project.
August 5-8, 1976
The 112th Anniversary Convention (Williamsburg) established the Student Advisory Council.
July 1, 1982
The Theta Xi Foundation converted from private foundation to public charity status.
June 20, 1986
Theta Xi was named the Outstanding Volunteer Organization for 1985-86 by the National Multiple Sclerosis Society.
August 9-13, 1989
Theta Xi celebrated its 125th Anniversary Convention (St. Louis) and adopted a Statement of Position on Fraternity Values.
December 5, 1991
Theta Xi was the initial recipient of Association of Fraternity Advisors (AFA) Excellence in Educational Programming for Values Into Action.
August 4-6, 1993
Theta Xi celebrated its 129th Anniversary Convention (Snowmass) and adopted the Core Associate Member Education Program and also reduced the maximum Associate Member period to 63 days. The Fraternity also adopted Habitat For Humanity as an alternate National Service Project.
Theta Xi received the Excellence in Educational Programming Award for Benchmarks of Excellence from the AFA. Theta Xi is the first fraternity to receive two Excellence in Educational Programming awards from the AFA.
July 27-30, 1995
Theta Xi celebrated its 131st Anniversary Convention (Pittsburgh) and established a chapter academic goal to obtain a Grade Point Average of 0.2 above the All Men’s Average. The Student Advisory Council was disbanded, adding a second undergraduate director to the Grand Lodge.
August 2-5, 2001
Theta Xi adopts the Strategic Plan during the 137th Anniversary Convention, setting a course for the Fraternity for the next 10 years.