Examples of tariffs stretch from Britain’s Corn Laws of 1815 to the reciprocal duties the United States imposed on nearly every trading partner in April 2025. A tariff is a tax a government charges on goods crossing its border, and each major example illustrates a different reason governments reach for the tool: protecting a domestic industry, punishing unfair trade practices, raising revenue, answering a national security concern, or pricing in something like carbon emissions. The cases below are the ones worth knowing, because together they show how tariffs actually behave once they hit the real world.
How a Tariff Rate Is Set
Before the examples make sense, it helps to know the forms a tariff can take. A specific tariff is a flat dollar amount per unit: $20 per imported bicycle, whether the bike costs $100 or $1,000. An ad valorem tariff is a percentage of the declared value, so a 10% duty on a $1,000 shipment costs $100. This is by far the most common form in modern trade. A compound tariff combines the two, charging a fixed amount per unit plus a percentage of value.
Tariffs also split by purpose. A protective tariff is pitched high enough to make imports more expensive than domestic alternatives. A revenue tariff exists mainly to generate government income, often on goods the country doesn’t produce at all. Most of the examples that follow are protective, because those are the ones that reshape entire industries.
The British Corn Laws, 1815 to 1846
One of history’s most studied tariff episodes began in 1815, when Britain’s Parliament passed the Corn Laws to protect domestic landowners and farmers. The laws placed steep import duties on cereal grains including wheat, barley, and oats. Harsh duties made buying grain from abroad unaffordable even when domestic supplies ran short.1The National Archives. The Corn Laws Grain prices stayed artificially high for decades, enriching landowners at the expense of urban workers who spent a large share of their wages on bread.
The laws finally fell in 1846 after the failure of the Irish potato crop made cheap grain imports a matter of survival. Conservative Prime Minister Robert Peel pushed through repeal over fierce opposition from his own party.2Encyclopedia Britannica. Corn Law The repeal marked a decisive shift toward free trade in Britain and remains a textbook example of what happens when tariffs protect a politically powerful minority at the public’s expense.
The Smoot-Hawley Tariff Act of 1930
The most infamous American tariff was signed into law on June 17, 1930, during the early months of the Great Depression. The Smoot-Hawley Tariff Act raised import duties on thousands of goods by roughly 20%, originally to shield American farmers from falling crop prices.3United States Senate. The Senate Passes the Smoot-Hawley Tariff Congress expanded the bill far beyond agriculture, and by passage, industrial products were covered too.
Trading partners retaliated almost immediately. About two dozen countries raised their own tariffs on American exports within two years, and international trade collapsed by an estimated 65% between 1929 and 1934.4Encyclopaedia Britannica. Smoot-Hawley Tariff Act Smoot-Hawley didn’t cause the Depression, but it deepened it by strangling the trade flows that could have helped economies recover. The episode is the standard cautionary tale against across-the-board protectionism.
The 2025 US Reciprocal Tariffs
On April 2, 2025, the President signed an executive order imposing an additional 10% ad valorem duty on all imports from every trading partner, effective April 5. A week later, on April 9, even higher country-specific rates kicked in for dozens of countries listed in an annex to the order.5The White House. Regulating Imports with a Reciprocal Tariff The stated goal was to rebalance trade deficits by matching the tariff and non-tariff barriers other countries impose on American goods.
That same day, a follow-up order paused the higher rates for 90 days, dropping most countries back to the 10% baseline. China was the explicit exception. The reciprocal rate on Chinese goods climbed to 125%, stacking on top of existing Section 301 and other duties to push the total well above 145%.6The White House. Modifying Reciprocal Tariff Rates In May 2025, the US and China reached a temporary agreement that cut the combined US levy on Chinese goods to roughly 30% for a 90-day window, while China dropped its retaliatory duties on American goods to 10%. In July 2025, the pause for other partners was extended, keeping their baseline at 10%.7The White House. Extending the Modification of the Reciprocal Tariff Rates The episode shows how fast rates can escalate when countries retaliate in sequence, and how pauses and bilateral deals create constant uncertainty for importers trying to plan.
Section 232 Steel and Aluminum Tariffs
Section 232 of the Trade Expansion Act of 1962 lets the President adjust imports that the Department of Commerce determines threaten national security.8Office of the Law Revision Counsel. 19 US Code 1862 – Safeguarding National Security In March 2018, the President used this authority to impose a 25% ad valorem tariff on steel imports and a 10% tariff on aluminum imports from most countries. The aim was to revive domestic production capacity that had been undercut by global overcapacity, particularly from China.
In June 2025, those rates were doubled to 50% ad valorem on both steel and aluminum from nearly all countries. The same 50% rate now applies to the steel and aluminum content in hundreds of downstream products, including wind turbines, mobile cranes, and railcars.9The White House. Adjusting Imports of Aluminum and Steel into the United States Extending the duty to downstream products addresses a pattern where manufacturers dodged steel tariffs by importing semi-finished goods that had already been shaped or welded abroad.
Section 301 Tariffs on Chinese Goods
Section 301 of the Trade Act of 1974 lets the US Trade Representative impose tariffs in response to unfair trade practices like intellectual property theft and forced technology transfer.10Office of the Law Revision Counsel. 19 US Code 2411 – Actions by United States Trade Representative The first round of Section 301 tariffs on Chinese goods took effect in 2018, covering industrial components and electronics at rates between 7.5% and 25%.11Federal Register. Notice of Action Pursuant to Section 301
In September 2024, those tariffs were sharply increased on strategic products. The updated rates show how targeted Section 301 can be:
- Electric vehicles: 100%
- Solar cells and modules: 50%
- Semiconductors: 50% (effective 2025)
- Lithium-ion EV batteries: 25%
- Lithium-ion non-EV batteries: 25% (effective 2026)
- Steel and aluminum products: 25%
- Ship-to-shore cranes: 25%
These are additional duties layered on top of normal tariff rates.12Federal Register. Notice of Modification – China’s Acts, Policies and Practices A Chinese-made electric vehicle, for instance, faces the 100% Section 301 duty plus whatever reciprocal tariff is in effect, pushing the total cost at the border to more than double the vehicle’s price. These layered rates are why so few Chinese EVs currently reach American consumers.
Anti-Dumping and Countervailing Duties
Not every tariff comes from a presidential proclamation. Anti-dumping and countervailing duties are trade remedies imposed after formal investigations by the Department of Commerce and the US International Trade Commission.13United States International Trade Commission. Trade Remedy Laws Administered by USITC
An anti-dumping duty targets a foreign company that sells a product in the US below its production cost or below what it charges at home. The duty is set to close the gap between the dumped price and a fair market price. A countervailing duty responds to foreign government subsidies that give exporters an artificial cost advantage. Both are designed to level the playing field rather than to protect or raise revenue in the traditional sense.14Enforcement and Compliance. An Introduction to US Trade Remedies
The two remedies frequently land on the same product at the same time, producing combined rates that dwarf typical tariffs. Certain Chinese steel products have drawn combined anti-dumping and countervailing duties exceeding 500%, reflecting findings of both heavy government subsidies and pricing well below production costs. The solar panel industry has been a frequent target too, with duties applied to panels and cells from multiple countries after investigations found dumping and subsidization. Each set of duties is product-specific and country-specific, and rates are recalculated through annual administrative reviews, so they shift over time.
Export Duties: Taxes on Goods Leaving a Country
Most tariff discussions focus on imports, but some countries tax goods going out. The US Constitution flatly prohibits this: “No Tax or Duty shall be laid on Articles exported from any State.”15Constitution Annotated. ArtI.S9.C5.1 Export Clause and Taxes Other nations face no such limit and use export duties for several purposes.
China has historically applied export duties and restrictions on rare earth elements, the minerals essential for EV batteries, wind turbines, and military equipment. Taxing or restricting rare earth exports lowers the domestic price of those inputs and gives Chinese manufacturers a built-in cost advantage over competitors in the US, Europe, and Japan. In April 2025, China tightened rare earth export controls further as a direct countermeasure to American tariffs. The strategy works because China dominates global rare earth mining and processing, leaving importers with few alternatives.
Developing countries with significant natural resources also use export duties as a straightforward revenue source and as an incentive to process raw materials at home rather than ship them abroad unfinished. Duties on timber, agricultural commodities, and unprocessed minerals encourage domestic refining and manufacturing capacity.
The EU Carbon Border Adjustment Mechanism
Tariffs are not exclusively a US tool, and the newest international example comes from the European Union. On January 1, 2026, the EU’s Carbon Border Adjustment Mechanism entered its definitive phase.16European Commission. Carbon Border Adjustment Mechanism CBAM functions as an environmental tariff. EU importers of carbon-intensive goods like steel, cement, aluminum, fertilizers, and electricity must purchase certificates based on the carbon emissions embedded in those products. The certificate price tracks the EU’s internal carbon trading market, so importers pay the same carbon cost that European producers already face.
If an exporting country already charges its own carbon price, the importer can deduct that amount. The mechanism is designed to prevent “carbon leakage,” where manufacturers relocate to countries with looser environmental rules and then export back into Europe. CBAM is a new category of tariff entirely: calibrated not to trade balances or national security, but to climate policy. Whether other countries adopt similar carbon border charges will be one of the defining trade questions of the next decade.