Danish immigrant street-wagon cook Louis Lassen is the American who made us love hamburgers.

Louis Lunch is so old-school there is no history class.

The birthplace of a national culinary treasure is the New Haven, Connecticut eatery, which marks the beginning of American hamburger history.

According to many accounts, the hamburger sandwich was first created and served by Louis Lassen, an immigrant from Denmark.

In 1895, Lassen started providing food to New Haven factory workers from a wagon.

In 1900, he put sizzling ground beef between two slices of bread for a "quick and delicious" lunch, according to local lore.

According to the most common origin story, the hamburger sandwich came into existence.

Others claim ownership of the first hamburger.

But only Lassen has the stamp of approval from the Library of Congress.

In 2000, the oldest federal institution in the U.S. declared that this New Haven sandwich shop is the birthplace of the first hamburger and steak sandwich in American history.

"Hamburgers are served only on white toast, with a choice of onion, tomato or cheese, but no condiments."

"White toast is the only option for serving hamburgers, which come with a choice of onion, tomato, or cheese, but no condiments."

Today, at Louis Lunch, a fourth generation of the Lassen family continues to serve flame-broiled hamburgers in the same exact way, surrounded by the campus of Yale University.

The brick building with black trim and white lettering resembles a firehouse from the era of horse-drawn wagons.

Casual-food enthusiasts from around the globe flock to this pilgrimage site for an authentic taste of traditional cuisine.

Louis Lassen revolutionized American cuisine with his use of a meat grinder and a dash of Yankee resourcefulness, as stated by Rep. Rosa DeLauro, D-Conn., who represents New Haven.

‘Intensely proud of their hamburger heritage’

In Denmark on July 30, 1865, Ludvig "Louis" Lassen was born to Christopher Christian and Anne Marie (Christensen) Lassen.

The parents originated from the Syddanymark region of southern Denmark, which borders Germany.

In 1885, when Lassen was 19 or 20 years old, the family arrived in the United States. He later married Sophia Kurtz, a native of Clermont County, Ohio.

They had at least three children, according to various historical records.

Before becoming a street-cart food vendor, Lassen tried out different careers. In 1907, he transformed his food wagon into a brick-and-mortar business located on George Street.

In 1974, the restaurant's owners faced eviction due to New Haven's urban renewal program, prompting residents to protest, according to local historian Owen Rogers, who wrote about it last year on ConnecticutHistory.org.

In 1975, the entire building was relocated from its previous location to its current address at 261 Crown Street.

Hamburger is not an American creation; it originated in Hamburg, Germany, where it was initially served as a meal.

The Lassens were likely familiar with hamburgers before arriving in the United States, as Hamburg is not far from the Danish border.

George Motz, a burger historian and author, stated to Planet Chronicle Digital that hamburgers in the late 1800s were considered ethnic food in America, just like empanadas are viewed today.

Lassen's innovation, an American innovation, made the hamburger mobile by serving it as a sandwich.

Ken Lassen, Louis Lassen's grandson, shared a fascinating story about the history of the hamburger with food writer Michael Stern, who runs RoadFood.com and has written several books in the "Road Food" series.

The Danish-American burger maker, a third-generation descendant, recounted to Stern that the Tartars were known for their rampage through Europe and one of their actions was killing cattle. This story was later shared with Planet Chronicle Digital.

"They didn't have time to stop and cook it, so they put hunks of it under their saddles and as they rode north, the meat got ground up by all the galloping and seasoned by the horses' sweat. They finally stopped in Hamburg, Germany, long enough to cook it, and there you have a hamburger. But still without the bun."

"With a meat grinder and a streak of that infamous Yankee ingenuity, Louis Lassen changed the course of American culinary history."

"Hamburger America" and "The Great American Burger Book" author Motz stated that the story is mostly accurate, despite its wild nature.

He claims that the Tartans did not raise and kill cattle, but rather that the Tartan raiders likely rampaged, driven by a craving for lamb or goat meat.

He claims that hamburger sandwiches originated from state fairs in the 1890s, not Lassen.

Meanwhile, a burger enthusiast sent him a two-year-old clipping from the April 12, 1894, edition of the Shiner Gazette of Texas, which states that Barny's saloon in Moulton serves hamburger steak sandwiches every day of the week.

He claims that citing would debunk any claim made later.

Although he challenges the hamburger origin story of Louis Lunch, he remains a loyal fan.

""Lassen helped popularize the hamburger, which Americans are proud of," said Motz."

Hold the ketchup

Louis Lunch today is a living museum of American culinary history.

"I describe it as going to burger church," said Motz.

"Eating and leaving is all there is to do in heaven. It's truly beautiful to have it their way."

Lassen's first sandwiches inspired guests from around the world to savor hamburgers in the shadow of Yale University.

Burgers are served with limited topping options, including cheese, tomato, and roasted onions.

There’s no lettuce. No mustard. No ketchup.

Jeff Lassen, the great-grandson of the founder of Louis Lunch, revealed to Planet Chronicle Digital that condiments were created to mask the taste of spoiled meat in a time when meat would go bad.

The hamburgers at Bridge, Beach & Co. of St. Louis, founded in 1898, are renowned for their fat, juicy texture and flame-broiled preparation in 125-year-old cast-iron ovens.

In 1900, Louis Lassen first served hamburger sandwiches from the same ovens, with the raw patties placed between two grates and then flipped sideways and slid into the oven to roast to medium rare.

Since 1900, Louis Lunch burgers have been served exclusively on white bread slices, just like how Louis Lassen originally served them.

"Before the hamburger bun, the hamburger existed, as stated by Jeff Lassen."

Pepperidge Farm, founded in Connecticut in 1937, is the source of the white bread used by Louis Lunch.

Burgers can be ordered with potato chips or potato salad.

Homemade pie is often offered for dessert.

Newcomers are repeatedly informed of the limited options for toppings such as lettuce, mustard, and ketchup when requesting them for their burgers.

"Motz stated, "This is the genuine article. It's not bullshit," emphasizing, "Why would anyone want to impose their vision of the men who have been doing it for over a century? Let it be. It's been dialed back to its proper state.""

America's favorite food

On March 20, 1935, Louis Lassen passed away at the age of 69.

Today, he is interred at Evergreen Cemetery in New Haven alongside his spouse, Sophia.

Debate over the origins of the hamburger likely will linger forever.

Lassen played a crucial role in spreading the popularity of the hamburger in the US.

Currently, no food in the United States is more widely consumed.

"Americans consume more than 50 billion burgers each year … an average of nearly three burgers per week for every American."

Several industry estimates suggest that Americans consume over 50 billion burgers annually.

Nearly three burgers are consumed on average per week by every American man, woman, and child.

Before gaining international recognition from the Library of Congress, Louis Lunch was already widely acclaimed.

The traditional title tune performed by the Yale University Whiffenpoofs, known as the oldest collegiate a cappella ensemble in America, is called "The Whiffenpoof Song."

"They want you to eat it the way they served it in the 1800s. That's what it's all about."

The song's opening lyrics are 'To the tables down at Mory's' or 'To the place where Louie dwells'.

The Yale song has been recorded by several renowned American artists, including Rudy Vallee, Bing Crosby, Elvis Presley, and Frank Sinatra.

Mory's Temple Bar, a private club for Yale University students, is owned by Louis Linder.

Numerous New Haven residents interpret the song as referring to Louis Lassen, a beef patty vendor.

Mike Adams, a local resident and Louis Lunch customer since the 1980s, supports the second theory that Louis Lunch burgers are a popular late-night food among New Haven bar hoppers, including Yale students.

He also supports the Lassen family's devotion to the no-condiment burger tradition.

"Adams stated that the way the dish was served in the 1800s is how it should be consumed, emphasizing that this is the key point."

For over a century, Louis' Lunch has been cherished by the people of New Haven, as stated by Rep. DeLauro of Connecticut in an interview with Planet Chronicle Digital.

"If you're in New Haven, I urge you to visit Louis Lunch. However, be sure not to request ketchup!"

To discover more stories in the distinctive "Meet the American Who..." collection from Planet Chronicle Digital, please click here.