The Ste-Croix Legacy Committee was established in 1996 as an international organization of Canadians and Americans to commemorate the Arrival of the French in North America with the arrival and settlement of the French expedition on Saint Croix Island, Île Ste.-Croix in 1604. On November 7, 1996, planning for the St. Croix 2004 Commemoration began in earnest with the establishment of the St Croix 2004 Coordinating Committee. The first meeting of this committee was held on May 3, 1997, and on April 27, 1999, the committee ratified a constitution and set of by-laws. In 2000 the Committee was incorporated as a not-for-profit corporation in Canada and the US, with their official logo revealed on June 25. In September of 2000 the committee hosted organizers of other 400th anniversary celebrations in Quebec and Nova Scotia at a day-long networking workshop in Calais. It launched its official bilingual Ste-Croix 2004 website in 2001, produced by the efforts of students from the New Brunswick Community College in Dieppe. Throughout 2001 the communities of Calais, St. Andrews, and St. Stephen committed to annual funding support. The committee led a number of events and exhibits in the years leading up to the 400th anniversary, including a cruise from St. Andrews to St. Croix Island in 2001, and the “It all started here-Nos premiers debuts” exhibit which was officially opened at Ross Museum for the 2003 summer season. Ste-Croix 2004 and the NB Culture and Sports Secretariat co-hosted the New Brunswick Heritage Week 2004 at the Vincent Massey Elementary School in St. Andrews, with focus on St. Croix, its history and the 400th anniversary.

On June 25th, 2004, the official opening of the commemoration was held at the Calais Town Square. The Famille Arsenault provided music. This event marked the beginning of ten days of town square entertainment in Calais, St. Stephen and St. Andrews, as well as historical lectures, quilt shows, dinners, genealogy fairs and other celebrations with a 400th anniversary theme. The 2004 Ceremony was led by Hugh Akagi, Passamaquoddy Chief. Simultaneously, the United States Parks Service hosted "The Meeting of Two Worlds 400 Years Later" on St. Croix Island, in which dignitaries such as US Ambassador to Canada, Paul Cellucci and Senator Viola Leger witnessed the Honourable Xavier Darcos, French Minister Delegate of Cooperation, Development and Francophony, present the French Legion of Honour to the Passamaquoddy Tribe represented by Lieutenant Governor Mark Altvater, Governor Robert Newell and Chief Hugh Akagi. Over sixty dignitaries were transported to the island by an armada of small power craft.

The Committee had plans for a legacy beyond the 2004 commemoration, with intentions for a major development of the interpretation site at Red Beach, just outside Calais, Maine, and the reconstruction of the Ste Croix Island habitation of 1604 at Bayside, NB, overlooking St. Croix Island. Negotiations for a land lease at the Bayside site continued with the Province until December when the request was turned down. A pending application for moneys from the federal government to assist with the recreation of the 1604 settlement was negated as a result of the Province's denial of a long-term land lease. The Ste-Croix Legacy Committee dissolved in 2005.