The first chapter of Pi Sigma Alpha was founded in 1920 at the University of Texas at Austin, and the society has grown over the years to over 700 chapters (as of 2012). A local chapter may be established at any college or university granting the baccalaureate or higher degrees, which is accredited by a regional or national accrediting association, and which offers a major sequence of courses in political science through an appropriate administrative department, school, or division of the institution, and which conforms to other requirements established by the Executive Council of the society. Chapters are guided by faculty advisors and by student officers.
Pi Sigma Alpha has programs to benefit its student members and their chapters, and the profession of political science. Programs for chapters and members include an annual Chapter Activity Grants competition, Best Undergraduate Student Paper and Best Undergraduate Honors Thesis awards, Scholarships for Graduate Study in Political Science, Scholarship for Washington Internships, Best Chapter awards, and Chapter Advisor Recognition awards. For the profession of political science, Pi Sigma Alpha sponsors major speakers at the annual meetings of the American Political Science Association (APSA) and the several regional and state political science associations, and provides Best Paper awards for the APSA Annual Meeting and the regional political science association annual meetings. It also co-sponsors APSA's annual awards for teachers of political science in higher education.
Pi Sigma Alpha is governed by an elected Executive Council, which acts as its board of directors. The Council includes the President, the President-elect, the three most recent past presidents, the Executive Director, the Newsletter Editor, the General Counsel, and twelve other members at large. Six of these are elected every two years to serve four-year terms. Members of the Council are almost always faculty of recognized distinction in the field of political science, or of proven leadership to the honor society. Elections take place in even numbered years at the Biennial Business Meeting of the honor society. The daily business of Pi Sigma Alpha is conducted by the National Office staff.