In 1980, Dr. John Hammond identified an opportunity to challenge youth to understand international forums by founding a Model United Nations conference for high school students at Kent State University's Ashtabula Campus. This program came to be known as KSUAC-MUNC. The conference came to be known as the Northcoast Conference and has been held annually at the end of March. Initially, the conference simulated three Security Councils with a few dozen students from surrounding Ashtabula County school districts and was staffed by just a dozen or so staff volunteers. Over the course of the next fifteen years, the conference grew substantially. By the mid 1990s, there were as many as ten Security Councils and several ad hoc committees being simulated. The number attending increased to more than 500 students from Ohio, Pennsylvania, New York, Michigan, West Virginia, and Ontario. The number of staff volunteers had increased to more than 100 from across the United States and Canada, including a Senior Staff that was established to assist Dr. Hammond with conference operations. This Senior Staff would eventually become the more codified Advisory Council.
In 1994, based up the success of the high school conference and with the devotion of a handful of Senior Staff, KSUAC-MUNC launched a conference for college students. This conference came to be known as the Lake Erie Conference and has been held annually at the end of October or beginning of November. Initially, this conference was attended by a few local colleges and was staffed by the high school conference's Senior Staff. Within a few years, this conference also grew substantially. The number of schools attending increased to roughly 20 colleges and universities from the across the eastern and midwestern United States and Canada. The number of staff volunteers increased to more than 50. By 2005, it was evident that the Lake Erie Conference had outgrown the confines of Kent State University's Ashtabula Campus. In 2006, the conference moved to its new home at the Crowne Plaza Cleveland City Centre in Cleveland, Ohio. In 2009, the conference moved to the Sheraton Cleveland Airport Hotel in Cleveland, Ohio.
In 2000, the Lake Erie International Model United Nations Corporation was created to ensure that Dr. Hammond's vision would continue well beyond his retirement from the operations of the conferences and from Kent State University. Bylaws and a Board of Trustees were created in order to guide and oversee corporate operations. In 2004, LEIMUN received its final 501(c)(3) non-profit, tax-exempt status. The corporation oversees both conferences and various corporate activities. In 2004, LEIMUN received its official 501(c)(3) non-profit, tax-exempt status.
In 2009, LEIMUN launched the LEIMUN Scholarship Fund. Annually, this Fund awards scholarships to 2 high school seniors.