How the national debt grew to $31 trillion

The United States owes $31 trillion. Washington now spends about $1 trillion more each year than it collects in revenue, forcing the Treasury Department to borrow to make up the difference. Which means the national debt is still growing.

Without big changes, the debt will soon be bigger as a share of the economy than when it peaked at the end of World War II. Most of that debt has accumulated over the past 20 years. In 2001, the nation actually had a cash surplus — the Treasury collected more in taxes than it spent on government services.

Since then, four presidents, 10 sessions of Congress and two wars have contributed to the tide of red ink. Thanks in part to policy decisions made generations ago, Social Security and Medicare are growing in cost, also adding to the debt. Although interest payments remain low by historical standards as a share of the nation’s economy, that could change quickly.

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