With all due respect to hamburgers and apple pie, hot dogs are arguably the most American of foods.

They owe their popularity and variety to immigrant entrepreneurs, for one. Plus, they are intended to be eaten in public, giving them a democratic aura. You can eat one while walking down a crowded city sidewalk, or while cheering at the ballpark. “It’s fast, it’s cheap, and it’s meat,” says food historian Bruce Kraig. “These are things that sell to Americans.”

Though we eat them all year round, they are quintessentially a summer food, associated with baseball and backyards. As Kraig puts it, “Even crappy hot dogs taste better out in the open.” Since most of them are sold pre-cooked, they don’t need to be prepared with particular care, and they withstand careless charring or undercooking. If you make it through the season without eating at least one hot dog, it’s fair to ask whether you’ve experienced the summer at all.

The hot dog is a simple concept—a sausage in a bun, that’s it—but it serves as a canvas for an incredible variety of ethnic and regional culinary experimentations. But no matter the toppings, at its core the hot dog boasts few pretensions. A tour of the history and culture of the American meal-in-a-hand reveals a story both humble and ambitious, befitting a beloved food that boasts the same qualities.

***

If anyone can be called America’s hot dog historian, it’s probably Bruce Kraig, a professor emeritus at Roosevelt University and long-time resident of one of the country’s great hot dog cities, Chicago. Kraig is the author of several articles and books about hot dog culture, including “Hot Dog: A Global History,” to which this account is indebted.

Sausages in general trace back at least to the first millennium BC.

Kraig finds them taking root as a public American food in the 1850s and 1860s, thanks to waves of German immigration. (A few decades later, Jewish immigrants propelled the rise of the all-beef dog.) Called frankfurters, red hots, or wieners in the early years, the sausages were hawked on boardwalks, streets, and during public events. In cities including New York, vendors manned pushcarts, with permanent hot dog stands becoming a fixture by the 1920s.

When it comes to the exact origin of the story of the hot dog as we know it today, apocrypha abounds, as it does with so many other great inventions. One popular and now-debunked story had it that New York baseball concessionaire Harry Stevens invented the dish in April of 1901. It was an unseasonably cold day at the Polo Grounds, and Stevens was caught off guard with only ice cream and cold soda on hand. To supply the chilly crowd with something warmer, he sent men out to buy up all the German sausages and rolls in the neighborhood, and topped the improvised sandwiches with mustard. Well-known New York newspaper cartoonist T.A. Dorgan was at the ballpark that day, the story goes, and sketched the brand-new sausage craze on the spot, calling the treats “hot dogs.”

It’s a nice story, which may be why it lingers so stubbornly, but it has been thoroughly debunked by scholars. That said, the exact linguistic origins of the words “hot dog” are still unclear. The term was popular on Northeast college campuses including Harvard, Yale, and Princeton by the mid-1890s. A lunch wagon at Yale called the “Kennel Club” became known as the “dog wagon,” and sparked jokey campus songs with lyrics like “‘Tis dogs’ delight to bark and bite, thus does the adage run. But I delight to bite the dog when placed inside a bun.”

A couple of years ago, Yale law librarian Fred Shapiro uncovered what is currently the earliest-known reference to “hot dogs,” in an 1892 edition of the Paterson Daily Press in New Jersey. In an article about ice-skating on Dundee Lake, a small boy orders a frankfurter on a roll by saying, “Hey, Mister, give me a hot dog quick.” The reporter explained: “The ‘hot dog’ was quickly inserted in a gash in a roll, a dash of mustard also splashed on to the ‘dog’ with a piece of flat whittled stick, and the order was fulfilled.” Kraig points out that the ongoing digitalization of historic newspapers means that discoveries like this are likely to become more common. The hunt for the proto-“hot dog” continues.

If Yale men didn’t coin “hot dog,” who did?

Following up on Shapiro’s discovery, linguist Ben Zimmer found one plausible contender in a man named Thomas Francis Xavier Morris, known in Paterson as “Hot Dog” Morris, who peddled frankfurters for years in the city. A black man born in the Caribbean, Morris had traveled all over Europe as a caged “wild man” in a circus, married a Swiss woman, and moved to the United States, where he worked as a cook in New York before moving to New Jersey and working as a hot dog peddler. “His stock in trade was always clean and neat,” the Patterson Daily Press reported in his obituary.

From the very beginning, diners have joked about hot dogs and sausages as “mystery meat” with questionable ingredients. The familiar song “Oh Where, Oh Where Has My Little Dog Gone?” originated as a joke about sausage meat, for example. The 1864 lyrics, written in a German “accent”:

Oh where, oh where is mine little dog gone;
Oh where, oh where can he be?
His ears cut short und his tail cut long:
Oh where, oh where is he?

Un sasage ish goot, bolonie of course,
Oh where, oh where can he be?
Dey makes um mit dog und dey makes em mit horse,
I guess de makes em mit he.

The suspicion around sausage meat was fueled by the fact that it was assembled by immigrants.

But it didn’t help that the foods really did vary widely in quality. Before the Civil War, sausages were made by hand, with finely chopped meat seasoned and then stuffed into intestinal casings. Linking sausages required skill, and it was a job that often went to women. Bit by bit, sausage-making became faster and tidier: The first steam-powered sausage meat chopper, which could cut 100 pounds of meat in 30 minutes, was invented in 1868; steam-powered stuffers were available in the 1890s. By the 1920s, power choppers could process up to 2,400 pounds of meat in an hour.

Manufacturers continually strove to make the process faster and smoother. At the 1939 World’s Fair in New York, Swift and Company introduced a fully automated sausage-making system that connected multiple stages of the process. Oscar Mayer was another key innovator, with a streamlined 10-lane processing system called the “wiener tunnel” or “hot dog highway.” Today, most mass-produced hot dogs are made with what Kraig refers to as “a slurry-looking mixture called an ‘emulsion’ or ‘batter.’” Did you really want to know how the sausage is made?

***

In the early handmade sausage years, buyers had to trust the butchers or salesman hawking them. Brand names came later. Take Oscar F. Mayer, who arrived in the United States as a teenager in 1873 and worked as a butcher boy in Detroit. He later worked as a buyer in the Chicago stockyards, and opened a butcher shop with his brother on the city’s German near North Side. The Mayers sold all kinds of meat, but then, so did many others. What set them apart was Oscar’s talent for branding: He sponsored booths at the Columbian Exposition in 1893, and sent delivery wagons across the city emblazoned with his brand. By the 1920s, the Mayer family began branding individual hot dogs by wrapping a paper label around each one. Then came the Wienermobile, wiener whistles, and the unforgettable jingle. By the 1960s, Oscar Mayer was an international brand, and hot dogs had become a food that families ate for dinner at home, not just when they were out and about.

Kraig places the heyday of the hot dog from the late 19th century through the 1950s, when hamburgers ascended as a public food. Today, sales are flat in the U.S., but that doesn’t mean they are small: In 2012, Americans spent $1.7 billion on hot dogs in grocery stores alone, according to the National Hot Dog & Sausage Council.

Even as hot dogs became mass-produced and standardized, they also became the site of extraordinary culinary innovation. Chili dogs were invented by Greek and Balkan immigrants in Detroit. Greeks in Chicago developed that city’s classic “garden on a bun” style, including pickle relish, tomatoes, and sport peppers. In New Jersey, you can buy deep-fried “Italian” hot dogs topped with potatoes, onions, and peppers.

So where does the hot dog go from here? Organic and humanely raised hot dog meat is ascendant in the U.S., according to Kraig. But like “fancy” hot dogs of all kinds—including those sold at the soon-to-close mecca Hot Doug’s in Chicago —it’s still a niche market. As for the classic American hot dog, its future may be overseas: Good old-fashioned ketchup-and-mustard hot dogs are wildly popular in countries including India and China. In the meantime, fast, cheap American meat isn’t going anywhere.