WASHINGTON, D.C.- In the U.S. it has become a political tradition that every April 24 the president issues a statement to recall and deplore the massacre of Armenians in Ottoman Turkey in 1915. These annual statements have the dual purpose of recognizing a 20th-century tragedy and catering to an influential ethnic constituency. Within a few years Armenian-Americans will have a new asset in their campaign to persuade politicians and others that what happened in 1915 was not just a spasm of mass killing but genocide. They are working to raise about $75 million to build an Armenian Genocide Museum and Memorial here to tell the story of this episode from the Armenian perspective. Plans for this museum not only touch nerves still raw from one of the last century’s bloodiest episodes. They also reflect a growing recognition by advocacy groups that museums can be powerful tools to advance political causes. The planned museum is to be the first of its kind outside Armenia. Planners have bought a stately classic revival building at the corner of 14th and G Streets, two blocks from the White House, which once housed the National Bank of Washington, along with three adjacent structures. The museum, scheduled to open in 2007, is to have 112,000 square feet for exhibition space and offices, making it about one-fourth the size of the Holocaust Museum. Ross Vartian, the museum’s director of planning, said Armenian-Americans were excited about the project, and in a recent memo to supporters of the museum he described its construction as a "sacred mission." Planners expect it to draw some 250,000 visitors a year. Both President Robert Kocharian of Armenia and Catholicos Karekin II, the Armenian Apostolic Church’s supreme patriarch, have given their symbolic blessing to the museum by visiting the site.