In this 2005 Journal-World file photo, Rosemary O'Malley, an eighth-grader at Central Junior High School, shops at Arizona Trading Co.

When Jennifer McKnight started Arizona Trading Co. at the age of 22, she didn’t have much beyond the used clothes she was selling, but apparently that was enough.

McKnight said the shop had no display shelves and didn’t even have a checkout counter at first until an old wooden one was dragged up from the basement of a nearby shop. She hung her offerings from the drop ceilings of the shop along with a disco ball, and that seemed to be all customers needed.

“Everybody was into it and supported us, and there was a lot of enthusiasm for it,” McKnight said. “And the first day we were opened, I paid rent for the entire month.”

Along with the disco ball, McKnight said she set up a little boom box as the shop’s “sound system.” She recalled her former striped and polka-dotted awning and that one of her early staff members wore roller skates to work, zipping over the old tile floors.

Initially, McKnight’s idea had been to spend a couple of years making money, then go back to school to finish her art history degree at the University of Kansas. But 30 years later, Arizona Trading Co. has become a fixture of Massachusetts Street.

McKnight said she got the idea for the shop after working at a similar store in Tucson, Arizona, which is where the Lawrence shop gets its name. She said that although there was a lot to figure out about running a business, once the shop was open she felt like she had found her thing. She said she really liked the concept of a buy-sell-trade store, not only because she loved clothes, but because she saw it as a fun and energetic business with environmental and community benefits.

“Instead of just doing traditional retail, where it’s just purely consumerism, with this you’re taking a wasted resource, basically everybody’s old clothes, and either helping people by paying them for their used clothes or by providing an easy, universally accessible way to change out your wardrobe,” McKnight said.

The store has also weathered challenges along the way. McKnight said that in the 1990s, two staff members left her store to start a competing buy-sell-trade clothing store downtown, which she said left her feeling betrayed as well as worried that downtown couldn’t support both businesses. And like other business owners, she’s worried about the rise of internet sales — and, more recently, the impacts of the coronavirus pandemic.

But the shop has made it through. After about five years, the other store closed, and though another used clothing store, Wild Man Vintage, subsequently took its place, McKnight said she saw Wild Man and her store as compatible. And though internet sales have indeed challenged retailers, McKnight said she thinks the shop is helped by the fact that it provides a service that is better in person.

“There is definitely a treasure hunt aspect to what we do, and that’s something you can’t really replicate on the internet,” McKnight said.

When it comes to the pandemic, McKnight has been one of a few retailers who have voiced concerns about the city’s plans to consider a permanent version of the downtown parklet program, which allows businesses to expand into the parking stalls directly in front of or alongside their storefront. Various restaurants and bars have used the program, and while she and other retailers have recognized the need for the program on a temporary basis, she said she hoped the city would also take into account the needs of downtown retailers as it considers what a more long-term program will look like.

Through it all, the shop has grown. In its early days, McKnight estimated that the shop operated with about five racks and maybe 3,000 pieces of clothing. Now, she said the shop has about 60,000 pieces of clothing on any given day, and that it turns over a store and a half of clothing about every month.

Though the disco ball and the polka-dot awning are no more, the shop has not necessarily lost its off-beat vibe, and McKnight said she still has the goal of trying to provide something for everyone. Reflecting on the accomplishment of 30 years in business, McKnight said she felt gratitude to Lawrence for giving the shop its start and sticking with it over the years.

“I just feel so happy and so gratified that I built something that our community loves so much and supports the way that it does,” McKnight said.

In addition to the downtown store, which is located at 736 Massachusetts St., McKnight runs another store in Kansas City, Mo., with the help of her business partner, Venus Nichols.