InterVarsity is one of the spiritual heirs of the Haystack Prayer Meeting that was held in August of 1806. As a small group of Williams College students met to pray for foreign missions, a summer storm forced them under the shelter of a nearby haystack. From that meeting, the American Foreign Missions movement began.
The centennial of that event was held in 1906. Plans are being made to mark the milestone once again next summer. An article at urbana.org has more details.
Another observance is being planned for the InterVarsity-sponsored Urbana 06 convention being in St. Louis, December 27-31, 2006.
