The U.S., Canada, and Mexico all agreed to delay the start of President Trump's tariffs and hold off,

at least for now, on the possibility of a trade war among allies. But the delay is only for a few weeks,

and as of now, there will be new tariffs taking effect tomorrow, 10% on goods from China. That's

already on top of tariffs on Chinese products and materials

dating back to President Trump's first term. President Trump also called the new tariffs on China

at, quote, opening salvo. And he spoke this weekend about his plans to issue new punitive tariffs

against another ally, the European Union. These threats and the prospects of a trade war lead to a number

of questions about how tariffs have been used in the past, what effect they've had, and their

potential impacts now. Economics correspondent Paul Solomon takes a closer look.

Tariffs. Taxes on imports to the U.S. collected at 328 ports of entry across the country.

Here's a look at some of the reasons President Trump gives to hike them.

Instead of taxing our citizens to enrich other countries, we will tariff and tax foreign countries to enrich our citizens. Reason one, to raise money from foreigners instead of tax foreign countries to enrich our citizens.

Reason one, to raise money from foreigners instead of taxing Americans.

President Trump insists tariffs were once the great revenue source for the United States,

and it's true.

Right up till the Civil War, tariffs raised 90% of the revenue for the federal government. But the federal government

was very small. Spending was like 2 to 3% of GDP. So there wasn't much to fund except for the debt

and the current expenditures and the tariff did it. Today, government spending is almost a quarter

of GDP. How much do tariffs bring in? Today it's only about 2% of federal revenue comes from the tariff.

It's just been swamped by corporate taxes, income taxes, Social Security taxes and things of that sort.

But the point is to replace those taxes. So how much more money can hire tariffs raise?

If you look at total federal revenues in a typical year, they're over $4 trillion.

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