Holiday Calendar

National Hamburger Month

Next celebratedSaturday, May 1, 2027

A food observance held throughout May celebrating the hamburger, its place in American cooking, and the start of the grilling season.

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Last updated February 26, 2026 · by the Holiday Calendar TeamHave an update or spot an error?
YEARLY DATEAll of May
OBSERVED INUnited States
CATEGORYFood
SUBCATEGORYBurgers
ORIGIN

Corporate Initiative

FOUNDING ENTITY
White Castle System, Inc.
FIRST OBSERVED
Not documented
“White Castle says it created the month, then dates its own founding to roughly 1991 in one release and 1993 in another.
HOW THE HOLIDAY CAME TO BE

A burger chain's month, with a founding year it cannot pin down.

White Castle, which calls itself the official sponsor of National Hamburger Month, says it created the observance to mark America's most familiar sandwich. The company gives conflicting start dates for it: a 2016 release framed that year as the 25th annual month, pointing to around 1991 or 1992, while a 2024 release said it introduced the month in 1993. No source independent of White Castle documents the creation.

INTRO

How a 13-week slider diet sold a nervous country on ground beef

In the 1920s, a hamburger chain set out to prove its food would not kill you. White Castle hired a University of Minnesota biochemist, handed a medical student a tray of sliders, and told him to eat almost nothing else for thirteen weeks. By the end he was reportedly putting away twenty to twenty-four little burgers a day, washed down with water, onions, and pickles. He walked away with a clean bill of health, and White Castle put that result straight into its advertising.

That is the strange backdrop to National Hamburger Month, the May-long celebration of a sandwich Americans now buy by the tens of billions.

The hamburger we eat today is less a single invention than a product of relentless standardization. National Hamburger Month is the calendar's nod to that machinery, and to the cooking season that arrives with the warm weather. It lands in May for a reason most cookout hosts already understand.

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ORIGINS

Hamburger Month history

INTRODUCTION

The hamburger did not start out as a sandwich Americans trusted. It started out as suspect meat. Ground beef carried a stigma, the cheap and easy place to hide spoilage, and one book made that fear national.

In 1906, Upton Sinclair published "The Jungle," his expose of the Chicago meatpacking industry. The book turned stomachs and hardened a lasting public distrust of ground beef. The question that hangs over the next half-century is a simple one: how did a food people feared become a food they eat roughly three times a week?

CHAPTER 01

Selling a clean burger in Wichita

The first answer came from a short-order cook. In 1921, Walter Anderson and an insurance man named Billy Ingram opened White Castle in Wichita, Kansas, often called America's first fast-food hamburger chain.

Anderson and Ingram engineered their way past the distrust. The name did the first work: "White" for cleanliness, "Castle" for permanence. The buildings were white porcelain-steel boxes with open kitchens, and customers could watch fresh beef get ground in front of them, twice-daily deliveries and all.

CHAPTER 02

The assembly line takes over

The next leap came from California. In 1948, brothers Richard and Maurice McDonald shut their San Bernardino drive-in for three months and reopened with what they called the Speedee Service System. They cut the menu from twenty-five items to nine, halved prices, fired the carhops, and ran the kitchen like a factory line.

That format became the template for modern fast food. Ray Kroc opened the first franchised McDonald's in Des Plaines, Illinois, in 1955, and the chain had sold over a billion hamburgers by 1963. The food historian Josh Ozersky would later call the hamburger "the most powerful food object in the industrialized world."

CHAPTER 03

A chain names a month

National Hamburger Month sits at the far end of that story, and its origin is the murkiest part. The only company that claims to have created it is White Castle, which describes itself as the observance's official sponsor.

How old is the month? White Castle cannot keep its own answer straight. One release marked a "25th annual" celebration in 2016, which points to around 1991 or 1992, while a later release said the company introduced the month in 1993. No independent record settles it, which leaves a corporate holiday whose own founder is unsure when it began.

WHY THIS DAY MATTERS

Why We Love National Hamburger Month

ECONOMY

A $173.6 billion industry gets one month on the calendar.

The US burger-restaurant business was worth about $173.6 billion across roughly 86,816 establishments in 2026, according to IBISWorld. National Hamburger Month is the calendar marker for a food that anchors one of the country's largest restaurant categories.

SEASON

It opens grilling season

May is the conventional kickoff of the American grilling and cookout season, anchored by Memorial Day weekend at the end of the month. The hamburger is the default thing on those first backyard grills, which makes the timing fit even if no source documents it as the reason.

STANDARDIZATION

It celebrates a manufactured food

The modern hamburger is a product of standardization, from White Castle's sanitized stands to the McDonald brothers' assembly line. The month quietly honors that industrial machinery as much as the sandwich itself.

BY THE NUMBERS

National Hamburger Month by the Numbers

~50B
US hamburgers eaten yearly
56.2 lb
Beef available per US person, 2021
$173.6B
US burger-restaurant industry, 2026
86,816
US burger restaurants, 2026

TIMELINE

Timeline

The Jungle shakes public trust

Upton Sinclair's expose of the meatpacking industry leaves Americans deeply wary of ground beef.

White Castle opens in Wichita

Walter Anderson and Billy Ingram build a clean, standardized burger stand to win that trust back.

The Speedee Service System

The McDonald brothers reopen in San Bernardino with an assembly-line kitchen that becomes the fast-food template.

First franchised McDonald's

Ray Kroc opens the first franchise in Des Plaines, Illinois, and the chain's modern corporation dates its founding here.

One billion burgers sold

McDonald's passes its first billion hamburgers, a milestone of industrial-scale cooking.

White Castle names the month

White Castle later dates its creation of National Hamburger Month to this year, though its own releases also point to around 1991.

GOOD TO KNOW

Surprising facts about National Hamburger Month

The test subject reportedly never wanted a burger again

One widely repeated account of White Castle's 13-week slider study says the medical student who ate them for science never willingly ate a hamburger afterward.

One chain expected half a billion May sliders

Marking the month in 2016, White Castle said it expected its Cravers to eat more than a half billion Sliders during the month of May alone.

The cheeseburger was trademarked, not invented, in Denver

Louis Ballast of the Humpty Dumpty Drive-In obtained a trademark for "The Cheeseburger" in Denver in 1935, then never enforced it.

Cravers have warmed up billions of frozen sliders

White Castle launched the first retail frozen sliders in 1987 and says customers have since heated up more than 6.5 billion of them at home.

GET INVOLVED

How to Celebrate National Hamburger Month

EDITOR'S PICK

Fire up the grill for the season opener

May is the unofficial start of cookout season, so light the grill and cook burgers over live fire. Treat it as the first backyard meal of the warm months.

GRIND

Grind your own beef at home

White Castle won customers by grinding beef in the open, so try the same transparency in your kitchen. Grind a chuck roast yourself and you control exactly what goes into the patty.

VISIT

Visit a chain with real history

Seek out a White Castle or an old-line burger stand instead of the nearest drive-thru. Eating where the format was invented turns lunch into a small history lesson.

HOST

Host a build-your-own burger bar

Set out patties, buns, and a row of toppings and let guests assemble their own. It turns a simple cookout into a shared event.

READ

Read up on how the burger was industrialized

Dig into the story of how a feared food became a national staple. The history of standardization explains more about the modern burger than any single recipe.

Test your knowledge

How well do you know National Hamburger Month?

1 / 8

Which company says it created National Hamburger Month?

Answer

It runs through the entire month of May in the United States, a stretch that also opens the country's grilling season.

COLOPHON

Sources

How we know what’s on this page. References, not endorsements.

11sources
3primary records
9independently dated
Primary records
White Castle2016-04-28
National Hamburger Month press release
White Castle's own claim that it created and sponsors the month, with its 25th-annual framing.
View source
USDA Economic Research Service2021
Food Availability and Consumption
Federal data showing 56.2 pounds of beef available per person in 2021 on an edible basis.
View source
PR Newswire2024-05-01
White Castle Showcases Archival Posters and Ads to Kick Off National Hamburger Month
White Castle's 2024 release dating the month to 1993 and noting 6.5 billion frozen sliders since 1987.
View source
Additional coverage
KCUR2023-03-22
How a Wichita hamburger stand changed the way America eats
How White Castle standardized and sanitized the burger after distrust from Upton Sinclair's work.
View source
Jack El-Hai2012-06-21
13 Weeks Eating Nothing But White Castle Hamburgers, in the Name of Science
The story of the medical student who ate only White Castle sliders for thirteen weeks.
View source
PBS SoCal2016-08-05
The Real McDonald's: The San Bernardino Origins of a Fast Food Empire
How the McDonald brothers' 1948 Speedee Service System turned the kitchen into an assembly line.
View source
EBSCO Research Starters
McDonald's restaurants and McDonaldization
Reference account noting McDonald's passed one billion hamburgers sold by 1963.
View source
Visit Denver
Denver: Birthplace of the Cheeseburger
Louis Ballast's 1935 Denver trademark for "The Cheeseburger," which he never enforced.
View source
PBS NewsHour2012-08-02
The hidden costs of hamburgers
The figure that Americans eat nearly 50 billion burgers a year, about three per person each week.
View source
IBISWorld2026
Burger Restaurants in the US, Market Size
The US burger-restaurant industry at $173.6 billion across 86,816 businesses in 2026.
View source
Smithsonian Magazine2009-05-22
Hamburger History
Historian Josh Ozersky calling the burger the most powerful food object in the industrialized world.
View source
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