When Bayard Winthrop, the chief executive of the retailer American Giant, ordered the batch of shirts that his company would advertise for the Fourth of July, he didn’t think much of it. The retailer, which has been producing its apparel solely in factories around the United States for more than a decade, perennially leans into its “Made in America” pitch for Independence Day.

This year’s batch of crew neck T-shirts are fittingly available in red, white or blue with very little embellishment other than getting straight to the point: Letters that read “American Made.” They cost $60 each. And they sold out in the first day. Then he ordered another set, which also sold out quickly as well. The company is scrambling to secure its fourth order.

For American Giant, this year is shaping up to be its most lucrative Fourth of July yet.

The company has been using its “Made in America” status to advertise to consumers since its founding in 2012. But, Mr. Winthrop said, it is now reaching customers at a time when chatter about the global supply chain, re-shoring, trade deal loopholes and sustainability in fashion has moved beyond corporate board rooms and policy circles in Washington.

Sixty-five percent of U.S. adults said they intentionally bought “Made in America” products over the past year, according to a Morning Consult survey released last month. That’s about the same rate of U.S. adults who said they had those intentions last year.

American Giant’s customer service representatives, Mr. Winthrop said, are receiving “emotional” emails from shoppers saying it’s “refreshing” to see a retailer “walking the walk” on making items in the United States.

“It really feels to me that there’s an awakening happening right now,” he said. “Consumers are intuitively understanding the backdrop to this conversation.”

Ahead of Independence Day in the United States, stores stack their shelves and populate their websites with T-shirts and swimsuits bearing American flag prints or slogans like “Party in the U.S.A.” A third of Americans say they plan to purchase patriotic fare for the Fourth of July this year, according to the National Retail Federation, a trade association.

The reality is much of that apparel is made overseas and imported. While there are retailers that in recent years have championed more domestic production, the Fourth of July causes particular tension because the items companies are pushing are patriotic only in theme.

Some competitors, who make their apparel stateside, are intentionally pointing out the disconnect.

“If you’re leaning into Americana to sell items that aren’t American made, I find it disingenuous,” said Kristen Fanarakis, the founder of Los Angeles-based fashion brand Senza Tempo and an advocate for locally made apparel.

Mr. Winthrop said, “One of the great ironies about the apparel industry, I think, is this kind of bizarre disconnect between what the industry says and what it does.”

Old Navy, for example, has been selling flag T-shirts for the Fourth of July since the company started in 1994. Yet, all of the 25 flag tops and baby onesies the company currently has displayed on its website are listed as imported. Searches for “Americana” and “Fourth of July” on Walmart and Target bring up T-shirts and shorts that are listed as imported as well. (Some of the apparel is listed as both being made in the United States and imported.)

Since the 1990s, production of apparel sold by major American retailers has largely moved overseas, especially to China, which brings heightened tensions between the United States and China into the equation for those companies.

The pandemic also strained the global supply chain, disrupting the reliability of imports. In some cases, retailers are moving production closer to the United States or sourcing a wider share of the goods they sell domestically.

In the past month, lawmakers in Washington have introduced a series of bills seeking to close off a shipping channel that allows companies like the fast-fashion retailers Shein and Temu — both founded in China — from benefiting from a trade rule, which allows them to forgo paying fees at U.S. Customs and Border Protection. Lawmakers argue this would level the playing field for American-based retailers.

The Fourth of July is one of Mr. Winthrop’s favorite holidays, but this year’s selling season has been so busy that he nearly forgot to snag one of his company’s “American Made” T-shirts for himself.

“I think I have found one in a retail store that is being sent to me, but I’m not sure,” Mr. Winthrop said. “It’s a bummer.”