In 1968, Sen. Strom Thurmond found himself stopped by a police officer in Greenville, South Carolina. His suspicious activity? Jogging.

Back in the 1960s, jogging was something only athletes and boxers really did. Normal people mostly didn't do it — and when they did, it was cause for concern. The New York Times ran an amused trend piece in 1968 on the handful of unusual freaks who chose to run in their free time.

Today joggers are everywhere, and we take them for granted (of course, we usually call them "runners"). But it took surprisingly long for jogging to break into the mainstream.

The earliest joggers attracted attention from the police

In 1968, the Chicago Tribune profiled the brave breed of "joggers" starting to appear in America. The truly ambitious ones would run for an entire mile.

The men profiled — the piece only featured men — said they ran in the morning because police became suspicious if they ran at night. The biggest theme was self-consciousness: The Tribune cited neighbors who "only see folly in the sight of a grown man running."

The following year, the Chicago Tribune found one restaurateur's jogging habit so notable that it ran another article about the strange hobby. The paper also investigated women's jogging fashion, another strange new trend (suggestions included a cashmere pullover).

"Can't I even run near my own home?"

The police were also alarmed by this weird new hobby. In 1968, the New York Times told the story of Dick Cordier, a Hartford, Connecticut, runner who was stopped by the police for "illegal use of a highway by a pedestrian." Cordier spent a day in court fighting a ticket. Likewise, Ray Crothers, a runner in the same city, evaded the police through alleys before calling his local police department and shouting, "Can't I even run near my own home?"

Jogging was such an unusual new fad that authorities didn't know how to handle it. That raises a question: Where did jogging come from in the first place?

We have New Zealand to thank for the jogging trend

Running obviously existed before the 1960s. But the specific practice of recreational jogging on sidewalks and roads for exercise was unheard of in the United States up to that point. Serious athletes did it before then, but normal people didn't.

Credit for introducing the concept probably goes to Bill Bowerman. A legendary running coach at the University of Oregon and a future co-founder of Nike, he said he discovered jogging on a trip to New Zealand in 1962. As he later wrote in Jogging: A Physical Fitness Program for All Ages, he was inspired by meeting with New Zealand jogging coach Arthur Lydiard, who had developed a cross-country running program. The prowess of the country's runners wowed Bowerman.

By 1968, jogging was having a moment

He brought jogging back to the United States, publishing a pamphlet on the topic in 1966. The next year, he released his best-selling book on the subject. Written with Dr. W. E. Harris, Jogging is justifiably credited with kick-starting a movement.

Crucially, he didn't just pitch jogging to fitness buffs — it was an activity for anybody who wanted to live a healthy life. The book built off Bowerman's research that jogging could help not just the waistline, but cardiovascular health. For instance, in 1965, Bowerman tested older men at the University of Oregon track. He showed, with the backing of medical experts, that jogging was good for them.

Following the endorsement of health professionals, the release of Jogging, and the cachet of athletes and celebrities who jogged, the new sport broke through to the mainstream. By 1968, jogging was having a moment — even if some people still didn't know how to react.

Jogging becomes mainstream ... and stops being a crime

The popularity of jogging only grew with the rise of celebrity runners in the '70s, when stars like Steve Prefontaine and companies like Nike continued to popularize the new sport. Other books furthered the conversation as well, like 1977's The Complete Book of Running, among many others.

Today we're used to seeing running shorts and tank tops everywhere, from the track to the grocery store. People stopped thinking jogging was unusual and started to do it themselves (and, thankfully, they stopped calling the police). In 1968, one jogger gave the New York Times his thoughts about the sport:

Today we've stopped staring at jogging — instead, we hardly notice it at all.

VIDEO: Figuring out why people run marathons