During his long career, Prince Tokugawa creatively promoted a friendship and alliance with six U.S. presidents and other world leaders during his extensive travels abroad. He was in many ways the diplomatic face of Japan when it came to international relations during the first 40 years of the twentieth century. Those years were often politically and socially turbulent, requiring Prince Tokugawa to take a leading role in encouraging respectful international diplomacy and military arms limitation at the Washington Naval Arms Conference. He strongly promoted an appreciation for democracy and during the 1920s took a leading stance against racism by introducing Abraham Lincoln's principles of equality into all of Japan's public schools and universities through Lincoln essay writing contests, where the winning students were gifted with bronze commemorative coins with the face of President Lincoln.