Administrators spent months planning and coordinating with dozens of different organizations in preparation for Monday’s event, which they later hailed as one of the most significant in University history.

About 1,500 people packed Lisner Auditorium to see the five former secretaries of state sound off on major issues facing the next administration. The audience included members of the diplomatic corps, the international press and about 1,000 members of the GW community.

Public tickets sold out 15 minutes after they were released on Sept. 4, University spokeswoman Tracy Schario said. A spillover crowd of about 30 people had to watch the event on a screen at the Jack Morton Auditorium.

University Police Department officers provided the only security at the event since Henry Kissinger, James Baker, Warren Christopher, Madeleine Albright and Colin Powell do not currently hold cabinet positions and did not require the Secret Service, Schario said. The University also alerted the Metropolitan Police Department.

Officials said the University paid less than $50,000 for the entire operation, which included a private luncheon at the Elliott School of International Affairs with the secretaries prior to the discussion and a reception afterwards. The secretaries did not receive payment for their visit.

GW shared payment for the event with the Center for New American Security, a D.C.-based think tank, Schario said. The Colin Powell Center for Policy Studies and Rice University’s James A. Baker III Institute for Public Policy were also partners in the planning.

Since the beginning of August, administrators held weekly planning meetings with partner organizations, but the entire event took almost a year to develop.

Ambassador Karl Inderfurth, who teaches a course on secretaries of state in the Elliott School of International Affairs, said he came up with the idea to bring former secretaries to campus for a discussion about a year ago.

Inderfurth, who formerly served as assistant secretary of state for South Asian Affairs, and his colleague Frank Sesno, a professor in the School of Media and Public Affairs and CNN special correspondent, began inviting the secretaries in the spring. Inderfurth said it was not difficult to get the secretaries to agree to come to GW, but it was a challenge to find a date that would work for all five.

“They are all out of office, but still in very high demand,” he said.

Adding the CNN broadcast element to the event came both from Sesno and from the University’s relationship with CNN, which once taped regular programming from GW, Vice President of Communications Mike Freedman said.

“An entity like CNN can’t just parachute into any institution in America and make something like this happen without engaging in a lot more legwork,” Freedman said.

Freedman said the event increased the visibility of the University and that functions like this will enhance GW’s reputation and prestige.

“It shows how GW has the infrastructure in place to make things like this happen,” Freedman said.

He joked the only thing he would have done differently would have been to “build about a 10,000-person auditorium” to accommodate all the students who could not get tickets.

Related: Secretaries of state meet in Lisner for historic event | Live blog