In 2013, federal government receipts (think taxes) totaled $2.778 trillion, while spending was $3.455 trillion, resulting in a 2013 deficit of $679.5 billion– 4.1% of GDP. The largest deficit ever was in 1943 during WWII when inflation adjusted; receipts were $250.8 billion and spending was $820.8 billion, leading to a deficit of $570.1 billion or 29.6% of GDP! Amazingly, seven of every ten federal dollars spent in 1943 were borrowed.