In 1999, we celebrate the 20th year of the annual Leafy Spurge symposium and the most aggressive battle ever waged against a weed in the Northern Great Plains. On June 26 and 27th of 1979, more than 125 scientists, legislators, land managers, farmers and ranchers met in Bismarck, North Dakota to discuss the increasing threat of leafy spurge to the land and livelihood of people in the Northern Great Plains. Leafy spurge had a good foothold by the time the first symposium was held. Introduced into North America from Europe and Asia, it had no natural enemies. A heavy seed producer and an aggressive root system allowed it to easily invade and become established on many sites. For about the first 50 years after introduction, it was primarily a problem in cropland, often spreading to new areas in seed grain. It did not cause much concern, particularly after WWII when herbicide use became common on cropland. Use of herbicides plus annual tillage generally kept leafy spurge from becoming an economic problem in cropland. It did become of greater concern in the 1960ís and early 1970ís when it began to appear in grasslands. Landowners found that the herbicides were not very effective on leafy spurge. But the attitude was that soon a new herbicide would be developed that would be the ìmagic bulletî for leafy spurge. In time, a ìmagic bulletî was available, but it was considered by most landowners to be too costly to use on lowvalue rangeland, and it did not always eradicate the treated plants. Landowners and public land managers did become concerned in the 1970ís. In response to their concerns, a multi-state/multi-agency steering committee was formed, which organized the 1979 symposium. The symposium consisted of technical papers on everything that was known about leafy spurge, followed by group discussions on the leafy spurge plant, chemical control, cultural control, biological control, and social and economic impacts. The reports from these discussion groups served as the basis for beginning an organized plan for research, education, and control of leafy spurge.