<P> Debt increased again during World War I (1914--1918), reaching $25.5 billion at its conclusion . Approximately $17 billion in debt was raised through the selling of Liberty Bonds to the general public to finance the U.S.'s military effort . The war was followed by 11 consecutive surpluses that saw the debt reduced by 36% by the end of the 1920s . </P> <P> Warren G. Harding was elected president in 1920 and believed the federal government should be fiscally managed in a way similar to private sector businesses . He had campaigned in 1920 on the slogan, "Less government in business and more business in government ." Under Harding, federal spending declined from $6.3 billion in 1920 to $5 billion in 1921 and $3.3 billion in 1922 . Over the course of the 1920s, under the leadership of Calvin Coolidge, the national debt was reduced by one third . The decrease was even greater when the growth in GDP and inflation is taken into account . </P> <P> Debt held by the public was $15.05 billion or 16.5% of GDP in 1930 . When Franklin D. Roosevelt took office in 1933, the public debt was almost $20 billion, 20% of GDP . Decreased tax revenues and spending on social programs during the Great Depression increased the debt and by 1936, the public debt had increased to $33.7 billion, approximately 40% of GDP . During its first term, the Roosevelt administration ran large annual deficits of between 2 and 5% of GDP . By 1939, the debt held by the public had increased to $39.65 billion or 43% of GDP . The buildup and involvement in World War II during the presidencies of F.D. Roosevelt and Harry S. Truman led to the largest increase in public debt . Public debt rose over 100% of GDP to pay for the mobilization before and during the war . Public debt was $251.43 billion or 112% of GDP at the conclusion of the war in 1945 and was $260 billion in 1950 . </P> <P> The public debt fell rapidly after the end of World War II under the presidency of Harry S. Truman, as the U.S. and the rest of the world experienced a post-war economic expansion . Unlike previous wars, the Korean War (1950--53) was largely financed by taxation and did not lead to an increase in the public debt . </P>

When has growth in the national debt been highest