The X-formation of palm trees at In-N-Out locations is a tribute to founder Harry Synder's love for the movie 'It's a Mad, Mad, Mad, Mad World'. The X-formation symbolizes the iconic scene in the movie where characters search for hidden treasure under a big 'W' made from palm trees.

On October 22, 1948, Harry and Esther Snyder opened the first In-N-Out drive-thru in Baldwin Park with a $5,000 investment, marking the beginning of the iconic fast-food chain's journey.

In 1961, the first Animal Style burger was created at In-N-Out in response to customer requests. It features a mustard-cooked beef patty served with pickles, lettuce, grilled onions, and extra spread. Originally a custom creation by early In-N-Out workers, it became popular among late-night customers.

In-N-Out ads and artwork often depict classic cars like 1965 Mustangs and 1968 Firebirds visiting the original restaurants, showcasing a nostalgic image.

In-N-Out ads and artwork often depict classic cars like 1965 Mustangs and 1968 Firebirds visiting the original restaurants, showcasing a nostalgic image.

In 1972, In-N-Out planted its first "crossed palm trees" at a restaurant inspired by a scene from the movie "It's a Mad, Mad, Mad, Mad World" where characters chase treasure buried under four palm trees resembling the letter W.

In 1973, In-N-Out celebrated its 25th anniversary with a total of 13 locations. Despite the rapid growth of rivals like McDonald's, the chain remained private and expanded slowly.

In 1974, In-N-Out launched its Cookout Department with an event using a grill and a pickup truck, introducing The Esther Snyder Cookout Truck that serves mini-versions of burgers and fries for special events like weddings, birthdays, and concerts.

In 1975, In-N-Out made a significant menu addition by introducing milkshakes to their offerings.

On December 14, 1976, Harry Snyder, the co-founder of In-N-Out Burger, passed away at the age of 63 after battling lung cancer, leading to a shift in leadership within the company.

In 1979, In-N-Out chain built its first restaurant with a dining room at its 21st store in Ontario, California.

In May 1982, Lynsi Snyder, the granddaughter of In-N-Out founders Harry and Esther Snyder, was born, eventually becoming the sole owner of the company and playing a significant role in its growth and development.

The university of In-N-Out Burger relocated to its own building in 1984 after operating out of store No. 1 in Baldwin Park for years.

In 1989, Rich, the son of In-N-Out founder Harry, emphasized the importance of maintaining the simple menu of burgers, fries, and drinks at the restaurant chain. He believed that adding more items would complicate operations and dilute the brand's identity.

In 1992, the first In-N-Out Burger restaurant outside of Southern California opened its doors in Las Vegas, marking the chain's expansion beyond its original location. This move signaled the beginning of In-N-Out's growth beyond its regional roots.

In December 1993, Rich Snyder, along with four other passengers, died in a plane crash on approach to John Wayne Airport in Orange County, California. The crash led to aviation safety regulations regarding wake turbulence.

In-N-Out Burger opened its 100th location in Gilroy, California on November 10, 1994, under the leadership of Guy Snyder. The chain expanded significantly during his presidency.

Guy Snyder, the brother of Rich Snyder, suddenly passed away in 1999 from an overdose of painkillers. His death resulted in the return of responsibility for the company to its co-founder and matriarch, Esther Snyder.

In 2000, In-N-Out Burger expanded its operations to Arizona, opening new locations and increasing its presence in the state.

In 2002, In-N-Out Burger was estimated to have generated $260 million in sales, showcasing its financial success and market presence.

In 2004, a famous incident occurred at In-N-Out where a 100x100 burger (100 patties, 100 slices of cheese) was ordered, leading to a policy change limiting orders to a maximum of 4x4.

In late December 2005, In-N-Out Burger celebrated the opening of its 200th location in Temecula, California, marking a milestone for the company.

In 2006, a lawsuit exposed a possible family disagreement within In-N-Out's corporate leadership. Richard Boyd accused Lynsi Snyder and other executives of trying to force out Esther Snyder. Boyd was suspended from his role as co-trustee, leading to a lawsuit and a settlement out of court.

In June 2007, In-N-Out filed a lawsuit against Chadder's restaurant in Utah for trademark infringement, claiming the restaurant's 'look and feel' too closely resembled In-N-Out. The lawsuit involved trademarked menu items like 'Animal Style' and 'Double-Double', leading to a temporary restraining order.

In 2008, In-N-Out Burger expanded into Utah by opening a location in Washington, Utah, and later adding more locations in northern Utah.

On January 1, 2010, Lynsi Snyder took on the role of president of In-N-Out Burger, continuing her family's legacy and contributing to the company's success as a prominent figure in its leadership.

In May 2010, In-N-Out Burger announced plans to expand into Texas, with the first locations opening in the Dallas–Fort Worth area in May 2011.

Lynsi Snyder, the granddaughter of In-N-Out's founders, gained control of 50% of the company in 2012 when she turned 30. She later gained nearly full control in May 2017.

In December 2013, In-N-Out Burger opened its first location in Austin, Texas, expanding its presence in the state.

On November 20, 2014, In-N-Out Burger opened its first location in San Antonio, Texas, continuing its expansion in the state.

In-N-Out opened its first location in Oregon on September 9, 2015, in Medford. This marked the company's expansion into the state.

On November 30, 2017, In-N-Out announced plans to build a production facility and distribution center in Colorado Springs, ahead of the company's expansion into Colorado.

On August 21, 2018, In-N-Out announced plans to open a location in the Willamette Valley in Keizer, Oregon, which became the company's northernmost location at that time.

In-N-Out Burger was ranked number 28 among America's Best Employers in 2019 by Forbes, showcasing its reputation as a top employer.

The first In-N-Out locations in Colorado opened in Colorado Springs and Aurora on November 20, 2020, marking the company's entry into the state.

On November 24, 2020, In-N-Out signaled its intention to open a store in Idaho, with the first store in Meridian opening in December 2023.

On January 10, 2023, Tennessee governor Bill Lee and In-N-Out president Lynsi Snyder announced plans for a new hub in Franklin, Tennessee, marking the company's expansion into the Southeast.

In-N-Out Burger plans to celebrate its 75th anniversary with an event at the In-N-Out Burger Pomona Dragstrip. The celebration will include drag racing, live music, and performances by the In-N-Out band .48 Special.

In-N-Out, known for its popularity in Southern California, is expanding its reach with the opening of a new location in Meridian. The move signifies the company's growth and expansion beyond its traditional market.

Jordan O'Dell is excited about visiting In-N-Out in the future.

In-N-Out Burger announced the closure of its only store in Oakland, California, on January 24, 2024, due to safety concerns related to crime. This marked the first time in the company's 75-year history that a location was shut down.

In 2026, In-N-Out will open its first restaurants in Nashville, Tennessee, becoming the closest locations to the East Coast for the chain.