Donald Trump ran for office, and has since governed as president, on a pledge to “Make America Great Again.” When, as a candidate, the New York Times asked him when he thought the US was last truly great, Trump said it was the beginning of the 20th century.

Perhaps not coincidentally, that was the last time the US was truly protectionist. The chart below shows the share of taxes collected on US imports since the country’s inception, a good proxy for protectionism. Way back in 1899 was the last time this number reached 30%. It was only 1.5% in 2016.

Trump’s proposal to impose tariffs of 25% on imported steel and 10% on imported aluminum should raise this number, if only slightly—steel and aluminum currently comprise a small share of imports, and for the moment key suppliers Canada and Mexico are exempt. Reports suggest that a package of tariffs targeting Chinese goods specifically are also in the works. If the Trump’s goal is to make America great again by making it more like it was 120 years ago, these actions fulfill that promise, at least in terms of trade.