In 1944 and 1945, William duPont, Jr. hosted three important tennis championships at Bellevue, bringing national recognition to his role in promoting tennis and to the sports center he created there. During World War II, when many tournaments across the country were canceled even as major events such as the U.S. Nationals continued, he offered Bellevue as a site for the Delaware State Women's Grass Court Championship after it lost its original location. In 1945, he again hosted the women's tournament and the United States Tennis Association's men's event, which featured second-ranked amateur Bill Talbert, who lived and trained at Bellevue, and third-ranked Pancho Segura. Margaret Osborne, later Mrs. William duPont, Jr., was the standout winner in both the 1944 and 1945 women's championships while competing against eight of the country's top-ten women players. The events were free and open to the public, overflow crowds watched from the grass incline, and Wilmington newspapers often remarked on William duPont, Jr.'s beautiful Bellevue Manor.