|Tau Delta Phi|
|Founded||June 22, 1910|
City College of New York
|Colors||Navy blue and White|
|Headquarters||1050 Connecticut Avenue NW, Suite 500|
Washington, DC 20036
Tau Delta Phi (ΤΔΦ), whose members are commonly known as Tau Delts, is a national social fraternity founded on June 22, 1910, in New York City. Since its inception, dozens of chapters have been founded and thousands of men initiated into its membership. Today, Tau Delta Phi fraternity operates five active chapters and colonies located primarily in the northeastern United States.
The predecessor to Tau Delta Phi was called Phi Sigma Beta, a high school fraternity founded on June 22, 1910. First established as a local fraternity, Phi Sigma Beta started at the Community Center of the Greenwich section of New York as a fraternity for Jewish men who were otherwise barred from fraternity life at that time. The founders had attended DeWitt Clinton High School. The group maintained itself as a single unit until 1912, when it became necessary to split in into two divisions, eventually three. Matriculating to several colleges, Alex Siegel, Milt Goodfriend and Max Coyne entered the City College of New York, becoming the Alpha class, initiating themselves under the new name of Tau Delta Phi on July 16, 1914. That same year, Gus Schieb and Leo Epstein created the Beta class at the New York School of Dentistry. Maxime Klaye, Samuel Klaye, Ben Gray and Mac Goldman created the Gamma class at New York University's School of Commerce. These "classes" became the first chapters as the founders moved into the collegiate phase of their lives. 
Soon to follow were a string of new chapters formed, beginning with Delta chapter at Columbia University in 1916. While the initial focus was on the New York metropolitan area, by 1917 interest from men outside of the area sparked the move to become a national organization, with the establishment of Epsilon chapter at Boston University. The decade saw a steady increase in membership. The "Pyramid" grew and expansion took its course from a regional to a national level.
By 1933 the fraternity had grown to nineteen chapters.
In 1934, Tau Delta Phi absorbed several chapters from Omicron Alpha Tau, a smaller Jewish fraternity with similar ideals, also active primarily in the Northeast. These included chapters at Rutgers, NYU, and Cornell.
The fraternity notes several "firsts": While formed to provide a fraternal experience for Jewish men, Tau Delta Phi became the first NIC fraternity to integrate by welcoming all races, creeds, ethnicities, and religions (1945), and was the first to open membership to include transgender, gender fluid, and non-binary members (February 2021).
Ironically, the integration that Tau Delta Phi pioneered may have been a factor in chapter loss during the 1960's through 1990's. That period showed a marked contraction of chapters coinciding with the period's adoption of integration by virtually all, if not all, other national fraternities.[a]
Tau Delta Phi hired an executive director for the first time in decades, in 2012. Since that time staff and volunteers have spearheaded a number of expansion projects, aimed to rebuild the fraternity.
The grand chapter of Tau Delta Phi Fraternity is the highest power. It convenes at every national convention and governs every aspect of the fraternity. It is composed of the executive council members, two delegates from each chartered chapter, the past living grand consuls, and one delegate from every alumni chapter in good standing.
The executive council is the board of directors of the fraternity. in between conventions, the Executive Council governs the fraternity. It is composed of all the grand officers and members of the board.
The Tau Delta Phi Management Company is a for-profit arm of the fraternity. It manages the finances of and provides support services to each House Corporation and issues a service contract for those services.
The Chapter House Corporation Each chapter should have a house corporation. House Corporations evaluate the property needs of each chapter and try to either rent, lease, or purchase a chapter house for each chapter. Each House Corporation has its own board of directors which are usually composed of fraters from their respective chapter.
The Tau Delta Phi Foundation is the nonprofit arm of the fraternity which seeks to support the educational mission of Tau Delta Phi and offer scholarships and grants to fraters of the fraternity.
The executive council of Tau Delta Phi is the supreme legislative authority between conventions. The board is composed of all the grand officers and the members of the board. The executive council is responsible for governing the fraternity and developing strategic plans to meet educational and brotherhood outcomes.
In 2012, the executive council hired its first full-time professional executive director in three decades. In 2014, the national office hired a graduate assistant and chapter consultant, who is able to visit chapters and colonies, and provide support for educational programs. The national office is host to the annual leadership conference, The Pyramid Leadership Institute.
These are the chapters of Tau Delta Phi. Active chapters noted in bold, inactive chapters noted in italics. 
|Alpha||June 22, 1910–19xx ?||City University of New York[b]||New York, NY||Dormant||[c]|
|Beta||June 22, 1910–1927||New York College of Dentistry (NYU)[b]||New York, NY||Merged||[c][d]|
|Gamma||June 22, 1910–1970, 1983–1988, 1992–20xx ?, 201x ?–20xx ?||New York University[b]||New York, NY||Dormant||Absorbed ΟΑΤ||[c][e]|
|Delta||1916–1931, 194x ?–1949, 1983–1985||Columbia University||New York, NY||Dormant|
|Epsilon||1917–1951||Boston University||Boston, MA||Dormant|
|Zeta||1918–1929||Harvard University||Cambridge, MA||Dormant|
|Eta||1919–1929, 194x ?–1991+||Massachusetts Institute of Technology||Cambridge, MA||Dormant||[f]|
|Theta||1920–1933||Illinois Institute of Technology||Chicago, IL||Dormant|
|Iota||1920–1970||University of Pennsylvania||Philadelphia, PA||Dormant|
|Kappa||1920–1928||University of Cincinnati||Cincinnati OH||Dormant|
|Lambda||1921–1935||University of Chicago||Chicago, IL||Dormant|
|Mu||1921–1923||Vanderbilt University||Nashville, TN||Dormant|
|Nu||1922–1935, 1947–1968||University of Michigan||Ann Arbor, MI||Dormant|
|Xi||1923–1968||Northwestern University||Evanston, IL||Dormant|
|Omicron||1924–1931||Ohio State University||Columbus, OH||Dormant||[g]|
|Pi||1924–1975||University of Illinois||Champaign, IL||Dormant|
|Rho||1926–1975||University of Texas||Austin, TX||Dormant|
|Sigma||1927–1933, 1948–1967||University of Southern California||Los Angeles, CA||Dormant|
|Tau||1927–1973||Lehigh University||Bethlehem, PA||Dormant||[h]|
|Chi||1928–1969||University of California, Los Angeles||Los Angeles, CA||Dormant|
|Phi||1928–1952||University of Minnesota||Minneapolis, MN||Dormant||[i]|
|Upsilon||1929–1942||University of North Dakota||Grand Forks, ND||Dormant|
|Psi||1929–1974||Carnegie Mellon University||Pittsburgh, PA||Dormant||[j]|
|Omega||1928–1952||University of Manitoba||Winnipeg, Manitoba, Canada||Dormant|
|Tau Alpha||1933–1972||Colby College[k]||Waterville, ME||Dormant||[l]|
|Tau Beta||1934–1971||Cornell University||Ithaca, NY||Dormant||From ΟΑΤ||[m]|
|Tau Gamma||1934–1976, 1993–199x ?||Rutgers University||New Brunswick, NJ||Dormant||From ΟΑΤ||[n]|
|Gamma Upsilon||1938–1958, 1962–1969||New York University (Heights)[o]||West Bronx, NY||Dormant||[o]|
|Tau Delta||1947–1968||University of Arizona||Tucson, AZ||Dormant||[p]|
|Tau Epsilon||1947–19xx ?, 19xx ?||New Jersey Institute of Technology||Newark, NJ||Active||[q]|
|Tau Zeta||1949–197x ?||Syracuse University||Syracuse, NY||Dormant||[r]|
|Tau Eta||1950–1968||Loyola University||Chicago, IL||Dormant|
|Tau Theta||1950–1959||Norwich University||Northfield, VT||Dormant||[s]|
|Tau Iota||1951–1976, 2008–201x ?||Rutgers University–Newark||Newark, NJ||Dormant||[t]|
|Tau Kappa||1952–1973||Queens College, CUNY||Queens, NY||Dormant||[u]|
|Tau Lambda||1952–1970||Alfred University||Alfred, NY||Dormant||[v]|
|Tau Mu||1953–1971||University of Miami||Coral Gables, FL||Dormant||[w]|
|Tau Nu||1952–1968||Hunter College, CUNY||New York, NY||Dormant||[x]|
|Tau Xi||1956–1971||LIU Brooklyn||Brooklyn, NY||Dormant||[y]|
|Tau Omicron||1956–1972||Temple University||Philadelphia, PA||Dormant||[z]|
|Tau Pi||1957–1968||Roosevelt University||Chicago, IL||Dormant|
|Tau Rho||1957–1968||Brooklyn College, CUNY||Brooklyn, NY||Dormant||[aa]|
|Tau Sigma||1962–1976||Pratt Institute||Brooklyn, NY||Dormant||[ab]|
|Tau Tau||1965–1973, 2009–2011||Pennsylvania State University||University Park, PA||Dormant||[ac]|
|Tau Upsilon||1966–1971||Michigan State University||East Lansing, MI||Dormant||[ad]|
|Tau Phi||1967–19xx ?||Seton Hall University||South Orange, NJ||Dormant|
|Alpha Delta||1967–19xx ?||Baruch College, CUNY||New York, NY||Dormant||[ae]|
|Tau Chi||1968–1970||University of Illinois Chicago||Chicago, IL||Dormant|
|Tau Psi||1970–1971||LIU Post||Brookville, NY||Dormant||[af]|
|Tau Omega||1969–1972||Texas A&M University–Corpus Christi||Corpus Christi, TX||Dormant||[ag]|
|Delta Beta||1969–1973||University of Maryland||College Park, MD||Dormant||[ah]|
|Delta Gamma||1969–19xx ?||Widener University||Chester, PA||Dormant||[ai]|
|Delta Delta||1969–200x ?||NYU (Tandon Engineering)||New York, NY||Dormant|
|Delta Epsilon||1969–19xx ?||William Paterson University||Wayne, NJ||Dormant||[aj]|
|Delta Zeta||1976–200x ?||SUNY, Farmingdale||East Farmingdale, NY||Dormant|
|Delta Eta||1975–200x ?||Cooper Union||New York, NY||Dormant|
|Delta Theta||1992–200x ?||SUNY, Stony Brook||Stony Brook, NY||Dormant||[ak]|
|Delta Iota||1994||Ramapo College||Mahwah, NJ||Active||[al]|
|Delta Kappa||1995–2018||Stockton University||Galloway Township, NJ||Dormant|
|Delta Lambda||1998–200x ?||Virginia Tech||Blacksburg, VA||Dormant||[am]|
|Delta Mu||2002–200x ?||Polytechnic University ?||Lakeland, FL ?||Dormant||[an]|
|Delta Nu||2004–2015||Christopher Newport University||Newport News, VA||Dormant||[ao]|
|Delta Xi||2008–201x ?||Caldwell University||Caldwell, NJ||Dormant||[ap]|
|Delta Omicron||2010–2012||George Mason University||Fairfax County, VA||Dormant||[aq]|
|Delta Pi||2012–20xx ?||Montclair State University||Montclair, NJ||Dormant||[ar]|
|Delta Rho||2013 ?||Kutztown University||Kutztown, PA||Active||[as]|
|Delta Sigma||2014||Rowan University||Glassboro, NJ||Active||[at]|
|Delta Tau||2014||Monmouth University||West Long Branch, NJ||Active||[au]|
|Delta Upsilon||2015–20xx ?||Jacksonville State University||Jacksonville, AL||Dormant||[av]|
The Wikipedia article for Omicron Alpha Tau lists a Marquette University chapter of that fraternity, noting it supposedly merged into Tau Delta Phi in 1934. But Baird's Archive has no listing of a Tau Delta Phi chapter at Marquette, in the ΤΔΦ article.