Who became 33rd president on Roosevelt's death in 1945 and was elected president in 1948 authorized the use of atomic bombs against Japan?

Harry S. Truman became the 33rd President of the United States upon Franklin D. Roosevelt's death in April 1945. He authorized the use of atomic bombs against Japan in August 1945, which played a significant role in ending World War II. Truman was later elected president in his own right in 1948.