Image caption Jeans are an iconic symbol of American fashion

Monte Galbraith has worked in the denim industry since he was a teenager. The 40-year veteran of the trade claims to have the indigo dye of blue jeans running through his veins.

Like many in Columbus, Georgia - a city on the banks of Chattahoochee River along the state's western border - Mr Galbraith followed his father into the textile mills.

Unlike most, he still works in the industry.

Columbus was once home to nine large textile mills, employing an estimated 20,000 people. Across the US there were more than a dozen denim manufacturers. Now there are just three.

"The textile industry in the US is just a shadow of what it used to be," says Mr Galbraith.

Trump's trade stance

The globalising world economy is cited as the reason for most of Columbus's mill losses, but locals also have a specific culprit for the demise of the US denim trade - the 1994 North American Free Trade Agreement (Nafta).

Media playback is unsupported on your device Media caption The firm keeping denim making alive in the US

Free trade, they say, forced American manufacturers to leave for cheaper shores or be undercut on price by foreign competitors. They left behind workers and communities who are still struggling two decades later.

The anger those losses created has been a driving force for Donald Trump's presidential campaign. In speech after speech he has slammed US companies for relocating factories to places like Mexico. Mr Trump has even pledged to renegotiate Nafta.

That rhetoric struck a chord with people like Mr Galbraith who have struggled with the consequences of free trade deals.

"I think the reason why Donald Trump initially grabbed so many people's attention, particularly mine, was his stance on trade," says Mr Galbraith. "He singled out Nafta - and Nafta absolutely transformed industries in this country."

Image copyright Getty Images Image caption Donald Trump says he will renegotiate Nafta, but some warn that this could hurt the US economy more than it helps

Economists have warned that Mr Trump's suggestion that he would impose tariffs on some of the US's largest trading partners could lead to a trade war.

But for those who lost their jobs or are struggling to compete with cheaper foreign goods, Mr Trump's message that the US will fight back against the pressures of a global economy is welcome.

Denim's downfall

Nafta did not just hit the textile industry; across the US factories making everything from shoes to cars began to close.

Jimmy Yancy, who works with the Columbus Chamber of Commerce, says the city knew it was too reliant on one industry.

Starting in the 1970s, Columbus began to diversify its economy, but it still never expected the losses from Nafta to be so dramatic.

By 1996 employment in Georgia's textile industry was just half of what it had been at its peak in the 1950s.

Image caption Swift Denim used to employ thousands of people in Columbus - this is what is now left of one of its mills

"I do think the realisation of the 21st Century is we are going to be living in a global economy, and we [are] going to have to be trading with other nations," says Mr Yancy.

"So we are going to have to figure out how we are going to survive and thrive in that environment."

That is a message that Democratic Presidential candidate Hilary Clinton is keen to promote.

In the past, she has supported free trade deals. She has called for more open economic borders. She praised the Trans-Pacific Partnership (TPP) free trade agreement while it was being negotiated.

Mrs Clinton has since said she would not support TPP in its current form, but she wants the US to remain a large player in the global economy.

Changing communities

Kimberly Oates Glover has first-hand experience of the impact on America's economy of increased international competition.

She started as a part-time cleaner for Swift Denim, aged 16, and worked her way up to office assistant, but in 1999 she was laid off as the company's business slowed.

Image caption Kimberly Oates Glover used to work in the Swift Denim mill and has witnessed Columbus's transformation

Today she works as an operations analyst for TSYS, a credit card processing company.

"Columbus was known as the textile city," says Ms Oates Glover. "Now we have a lot of technical jobs. I call them the new mills because now the kids in high school want to work at one of those jobs."

Ms Oates Glover has seen Columbus change from a textile town, a struggling city, and now to the home of several data processing centres.

A few of her old colleagues also found jobs at TSYS, but she says they lost the camaraderie they had at the mill.

"It's not the same," she says. "You are locked up in cubicles. You punch in and punch out. At [Swift] it was more physical but you moved around and saw each other."

Image caption Columbus has transformed some of its old mills into flats and artist studios

Swift helped pay for her college education, which helped her. But many older workers were less successful at retraining for jobs in Columbus's modernising economy, and were forced to settle for lower paid hourly work at places like Wal-mart.

Ms Oates Glover does not plan to cast her vote for Donald Trump because she doesn't feel he has the right temperament for the role. But like many in this area, she is sceptical of Hilary Clinton and what her policies will mean for jobs and the economy.

The effect of trade deals has turned many areas of once-booming cities across the US into ghost towns. The reliance on a single factory or single industry sometimes cost cities nearly all their jobs when that work moved overseas.

Columbus has not fared as badly; its downtown area has been revitalised, and old mills have been turned into loft apartment and studio spaces.

But there is no doubt that Mr Trump's talk on trade has awakened a struggling section of the US that is resisting the globalising economy.