Pennsylvania Avenue, the heart of the historic site, is recognized by many as "America's Main Street." The avenue plays a significant part in American political culture as well. "Since its creation in the head of L'Enfant, from the time Jefferson planted Lombardy poplars along its edge, this has been the most important avenue in Washington," noted author Jeffrey F. Meyer. "It is the corridor of power, linking the legislative, judicial, and executive branches." Professor of architecture Michael J. Bednar, commenting on the role the avenue plays in the nation's political life, has written, "A march down Pennsylvania Avenue...brings high visibility and prestige to a group and its cause." Historian Lucy G. Barber, who has studied the site's political meaning, has called it one of the "central and most potent national spaces of the nation." The American Planning Association said in 2014 that a "march down Pennsylvania Avenue holds great symbolic meaning and has played a role in the fight for workers' rights, women's suffrage, and civil rights."