Over 100 years ago Cognac, France and Denison, Texas shared two of it's citizens with the world to solve a major destructive force - the grapevine destroyer, phylloxera. It was 1880 and the phylloxera plague was rampant in France, especially in the Charante Region where Cognac is located. The phylloxera root louse was destroying the prestigious French winegrapes and therefore, destroying the economy of France. France assigned the preeminent French scientist, Pierre Viala the task of finding a cure for the phylloxera plague. This investigation brought him to the United States and to the home of Thomas Volney Munson in Denison, Texas. The two scientists collaborated on the problem for several days in Denison and various other locations in Texas to view the native grapes of Texas in their natural habitat. For you see, the soils of the Charante and Denison are very similar and therefore should have grape species capable of growing in either location. T. V. Munson suggested that the only way to save the French vineyards was to graft the Vitis vinifera varieties to resistant rootstocks. Munson knew that the Texas rootstocks were resistant to phylloxera and at his suggestion, Pierre Viala agreed that it was a good plan of action. Thousands of bundles of Texas rootstocks were shipped to France where Pierre Viala and other French scientists started educating the French winegrowers on the enormous grafting tasks that lay ahead. The grafting literally continues to this day.

For his monumental contributions to France, T. V. Munson was awarded the highest award that could be given a foreign civilian, the Chevalier du Merite Agricole and was inducted into the Legion of Honor in 1888.To commemorate the award 100 years later, a Centennial Celebration was held in 1988 in both Cognac and Denison where identical plaques were presented to each city and official delegations visited in both countries. While the Denison delegation was in Cognac, Mayor Francis Hardy asked David Munson of the W. B. Munson Foundation, to investigate the possibility of establishing a formal relationship between the two cities. This was accomplished and in October of 1992 a delegation from Denison went to Cognac and in a formal ceremony established the Sister City relationship. In a reciprocal visit, an offical trade delegation from Cognac was in Denison in October 1993 to begin the economic development strategies between the two cities. Upon arrival of the Cognac delegation, Denison Mayor Ben Munson stated, "This Sister City relationship marks the beginning of an international economic development venture which will significantly benefit the peoples of Denison and Cognac for generations to come." Educational and professional exchange programs were to be implemented in 1994.

Economic development and trade are of paramount interest to both cities, and with a relationship that spans over 100 years, this new international venture should mature rapidly and reap great rewards to both great cities.