Certainly! Here's a revised version of your statement that clarifies the connection between Franklin Delano Roosevelt's death and his lasting impact:
"Today marks the 54th anniversary of Franklin Delano Roosevelt's death, which occurred on April 12, 1945. Roosevelt was instrumental in mobilizing the American people and the world during a time of great turmoil, leading courageous soldiers to fight in World War II. By referencing this significant date, we can better understand the enduring impact of Roosevelt's leadership decisions and the legacy he left behind."