By the early 1870s, Strauss was a well-established and respected businessman and a supporter of the Jewish community in San Francisco, and that could have been his legacy. However, in 1872, one of his customers and a fellow immigrant (from modern day Latvia), Jacob Davis came to him with a business proposal. Davis, a tailor living in Reno, Nevada, had been producing white canvas waist overalls (the name for work pants at the time) for his customers by placing copper rivets at “points of strain,” including pocket corners and the seam below the button fly, thereby creating a garment that could withstand the work life of miners and other hard laborers of the time. Davis wanted to patent his idea to protect himself from imitators, but didn’t have the money or the means of production to move forward on his own—which is where Strauss came in. After receiving a handwritten letter from Davis, Strauss agreed to go into business together and, on May 20, 1873, a patent was granted to the two men for “Improvement in Fastening Pocket-Openings.” Almost immediately, Strauss and Davis began producing waist overalls out of brown cotton duck and true blue denim fabrics, initially employing seamstresses who worked out of their homes and then moving to a manufacturing facility in San Francisco. The waist overalls featured a single back pocket with the soon-to-be-famous arcuate design, a back cinch and, of course, rivets at points of strain on pockets and the crotch.

It’s important to note here that, although the two men are responsible for the creation of jeans, Strauss and Davis did not create denim, which has its own complex history that dates back to 17th century France and England, which were producing a silk and wool fabric called “Serge de Nimes,” and Italy, which was producing a cotton, linen and/or wool blend fabric called “jean.” By the eighteenth century, jean and denim (a supposed descendant of Serge de Nimes) were both entirely made out of cotton, although jean was woven from two threads of the same color, while denim featured one white thread and one dyed thread; denim was also known for its superior durability. According to former Levi’s historian Lynn Downey, the first known reference to denim in the U.S. comes from 1789 when George Washington toured a textile factory in Massachusetts.

By the 1880s, Strauss and Davis had established their own factory south of Market Street and were producing their XX waist overalls (the “XX” stood for “extra strong”), the precursor to the now legendary 501, using denim fabric from Amoskeag Manufacturing in Manchester, New Hampshire, a textile mill incorporated in 1831, which had been producing denim since the mid-1860s. In 1886, Strauss and Davis introduced the “Two Horse” logo, knowing that their patent would expire in 1890 and that they needed a way to communicate the strength and durability of their product, especially in the remote West where not everyone spoke English or was literate. The logo—which depicts two horses pulling in opposite directions on a single pair of jeans, trying unsuccessfully to tear them apart—was so popular that Strauss and Davis’s company was known as The Two Horse Brand until 1928, when it officially adopted the Levi's trademark.

1890 was a big year for the brand that would eventually be known as Levi's. Davis, Strauss and his nephews—Jacob, Sigmund, Louis and Abraham, who he brought on not long after their father, David Stern died in 1874—officially incorporated the company and gave their XX waist overalls the 501 lot number. According to Complex, at the time, the “5” in 501 stood for Levi’s highest quality product; they also made lower quality 201 waist overalls. In 1895, the company introduced its first bicycle pants, a hundred and sixteen years before it would debut Levi's Commuter. And, in 1901, Levi's debuted waist overalls with two back pockets.

Strauss also continued his philanthropic work throughout the 1890s and into the turn of the century. He contributed to the Pacific Hebrew Orphan Asylum and Home, the Eureka Benevolent Society, the Hebrew Board of Relief, provided scholarships to the University of California, Berkeley and even helped fund a new railroad from San Francisco to San Joaquin Valley (which never came to fruition). In 1902, Strauss died peacefully in his home, leaving the company to his nephews and his six-million-dollar fortune to his nephews and a selection of charities including the Pacific Hebrew Orphan Asylum, the Home for Aged Israelites, the Roman Catholic and Protestant Orphan Asylums, Eureka Benevolent Society and the Emanu-El Sisterhood.

On April 18, 1906 the great San Francisco earthquake and fire destroyed numerous buildings in the city, including the Levi Strauss & Co. headquarters at 14-16 Battery Street and the company’s factory. The brand lost all its dry goods, furnishings and business files including any records of what the arcuate back pocket design means (although there is a theory that it represents the wings of an eagle). Undeterred, the Stern brothers decided to build a new factory and continued paying employees’ salaries. Around the same time, Jacob Davis sold his share in the patent and production of Levi Strauss & Co., but continued to work as the head of the brand’s factories until his death years later.

Despite the setback from the San Francisco earthquake and fire, Levi Strauss & Co. continued to expand. By 1915 the demand for the brand’s waist overalls was so great that the Stern brothers began buying the majority of their denim from Cone Mills in North Carolina. Cone had been founded in 1891 and established itself as the leading denim manufacturer in U.S. only ten years later. According to former Levi's historian Lynn Downey, the brand made the change because by “the end of the 19th century Amoskeag and other New England mills had begun to experience a slow decline, due to competition from mills in the southern states, higher labor and transportation costs, outdated buildings and equipment and high taxes.”

In 1918, Levi Strauss & Co. had the foresight to explicitly double its customer base and expand into womenswear. Women were taking on larger roles in the American West—in part, due to WWI—and the brand saw an expanding market for women’s workwear. The first product line the brand introduced was called “Freedom-Alls” (a nod to both the country’s involvement in the war and women’s expanding roles in society) and featured workwear suits that included belted tunics paired with matching relaxed trousers that buckled near the ankle. The first versions came in “heavy khaki” and “lightweight cotton,” but Levi's soon introduced iterations that paired solid blue, pink and green tunics with matching striped trousers. However, it seems that Freedom-Alls may not have been a resounding success, since they vanished from the brand’s product catalog only a year later.

1922 saw Levi Strauss & Co. switch entirely to Cone Mills Denim and introduce its first pair of waist overalls with belt loops. During the decade, the brand’s waist overalls became the leading seller in men’s work pants in the Western United States. In 1928, Levi Strauss & Co. registered the Levi's trademark that has helped define the brand for the past ninety years.

Levi's continued its ascent into the ’30s despite the increasingly tumultuous state of the world. In 1934, the brand introduced Lady Levi's, its first waist overalls for women, made of pre-shrunk denim and featuring many of the same details on the men’s 501®. Two years later, the brand debuted its Red Tab, which was placed on the right back pocket of its waist overalls and, at the time, featured the word “LEVI”S®” stitched in white capital letters. The ’30s was also the decade that marked Levi's arrival into the canon of American pop culture and solidified denim as a part of the mythology of the American West. The brand’s waist overalls were featured in films, in particular John Ford’s aforementioned 1939 masterpiece Stagecoach, starring John Wayne. The appearance of Levi's in films not only gave the brand a cool factor that elevated its waist overalls above their workwear origins, but it also inspired Easterners who wanted the authentic cowboy look to head west of the Mississippi to dude ranches in order to buy their first pair.

With the U.S.’s entrance into WWII in 1941, Levi's saw its production of waist overalls drop, since raw materials were needed for the war effort; the brand also made changes to its to comply with the requirements of the War Production Board, using paint instead of thread for the back pocket Arcuate, scrapping the back waistband cinch and removing the watch pocket and crotch rivets. As the U.S.—and the rest of the world—emerged from the terrors of WWII, Levi's sought to reestablish its prewar prominence. Starting in the ’50s, the brand began selling its products in the Midwest and the East and began eyeing foreign markets as well. People in places as widespread as Thailand, England and Pitcairn Island in the South Pacific wrote Levi's about buying their waist overalls after seeing them on American G.I.s.

Levi's also found creative ways to take advantage of press opportunities, such as in 1951 when singer Bing Crosby and a friend were initially denied entrance to a Vancouver hotel due to their hunting gear, which included Levi’s waist overalls (eventually a bellhop recognized Crosby and the men were admitted). As a marketing ploy, the brand created a denim tuxedo jacket for the singer, made from 501® denim and decorated with a corsage constructed from Red Tabs secured with copper rivets. A patch on the inside of the jacket featured Crosby’s name and the statement, “Notice: To All Hotel Men Everywhere, Label entitles the wearer to be duly received and registered with cordial hospitality at any time and under any conditions” in all caps. The brand presented the tuxedo to Crosby at the 1951 Silver State Stampede in Elko, Nevada, where he was the honorary mayor, and he went on to wear it during press appearances for the film, Here Comes the Groom.

1954 saw Levi's produce its first pair of waist overalls with a zipper fly to appease its customers in the Midwest and the East who weren’t as fond of traditional buttons. The brand also introduced its Denim Family line to capitalize on denim’s increasing appeal as a leisurewear fabric; at the time, Levi's was marketing its waist overalls to parents as “Right for School” for their children. However, while the company was trying to turn denim into the ubiquitous fabric of the “average” American, Hollywood was showcasing waist overalls as the go-to pants of outlaws and outcasts; no film is more indicative of this representation than Laslo Benedek’s The Wild One, released in 1953 and starring Marlon Brando as motorcycle gang leader Johnny Strabler. Dressed in Levi's denim, a white ringer t-shirt, a Schott Perfecto motorcycle jacket and engineer boots, Brando’s Strabler helped fashion a new image of American cool that has persisted until today. And, despite a letter or two from stuck-up Northeasterners who bought into newspaper reports about “motorcycle boys,” Levi’s achieved its goal of ubiquity by the end of the decade. According to former Levi's historian Downey, a 1958 newspaper article reported that “...about 90 percent of American youths wear jeans everywhere except ‘in bed and in church’ and that this is true in most sections of the country.”

The widespread success of Levi's in the ’50s convinced the brand to rename their waist overalls “jeans” starting in 1960. Most of Levi's new, young customers were already calling the brand’s denim pants “jeans” by then, most likely as a shorthand for “jean pants,” a term that referenced the jean fabric (along with denim) that was often used to produce workwear; Levi Strauss himself imported “jean pants” from the East Coast to sell in San Francisco. The ’60s saw Levi's usher in a number of other changes as well. In 1961, the brand introduced Slim Fits, a five-pocket twill trouser that teenagers dubbed White Levi's, which the brand hired Jefferson Airplane to remix their song “White Rabbit” for in 1967. The early ’60s also saw Levi's sell its first pre-shrunk jeans for men and, in 1964, the brand patented the Sta-Prest® process, which creates permanent creases in pants and shirts. Levi's biggest move of the decade came in 1965 when the company created an international division to organize and expand its distribution to Europe and Asia, pushing jeans to become a truly international icon. And, with icons in mind, the brand introduced its “batwing” logo—based on the shape of the top half of the back pocket, including the arcuate, of a pair of its jeans—in 1967.

As the popularity of straight-leg denim waned in the ’70s, Levi's introduced a range of other fabrics, patterns and silhouettes from plaid to polyester to no-wrinkle flares with matching vests. In 1971, the brand went public, and also made a more subtle adjustment when it lowercased the “e” on its Red Tab. Levi's also made a concerted effort to maintain the relevance of denim in the ’70s by announcing its Denim Art Contest in 1974, a decision that seems prophetic today with fashion’s current movement toward customization and DIY aesthetics. The contest invited consumers to submit photos of their decorated jeans and denim jackets with the winners going on an eighteen-month tour of American folk art museums. Over 2000 contestants submitted photos, including second place winner Hopeton Morris, who repurposed bottle caps and hair color samples to create a decorative denim jacket that looks like a Levi's collaboration with Saint Laurent or Balmain. The winners’ garments were also showcased in a book, The Levi’s Denim Art Contest Catalogue of Winners, published by photographer Baron Wolman.

The late ’70s and early ’80s saw Calvin Klein usher in the age of designer jeans with the help of suggestive ads staring a teenage Brook Shields. In response to the subsequent explosion of designer denim in the ’80s and ’90s, Levi's pushed back with its “501 Blues” commercials and, later, its own suggestive ads, inspired by representations of its jeans in Post-WWII America that, unfortunately, but unsurprisingly, featured almost exclusively white casts. The brand continued to feature its 501 silhouette, albeit often in stone-washed iterations that ironically owe their existence to designer denim, since the process was created by French design duo François and Marithé Girbaud, who were also responsible for introducing the baggier silhouettes that would later compete against straight leg denim. The ’80s also saw Levi's produce clothing for Olympic athletes (for the 1980 and 1984 games) and debut its Dockers brand, in 1986, to appeal to baby boomers in need of office casual clothing.

In 1985, Robert D. Haas, president and chief executive of Levi's and the great-great-grandnephew of Levi Strauss, [bought out the firm for $50 a share]*http://articles.latimes.com/1985-07-12/business/fi-9096_1_robert-d-haas) with the help of other descendants of Strauss who also owned stock in the company. In 1987, Levi's Japan began producing vintage-inspired jeans that would become the inspiration for the brand’s 1996 introduction of Levi's Vintage Clothing, which, unfortunately, was too far ahead of its time. Although Time named the 501® jean the “Fashion Item of the Century” in 1999 and the brand introduced “Engineered Jeans,” reverse engineered versions of its classic silhouette, all was not well. That same year, the brand closed eleven American factories and laid off 5,900 employees (30 percent of its North American workforce), moving much of its production overseas; in 2004, Levi's closed its remaining manufacturing plants in the U.S. and Canada. While many brands were moving toward boutique retail and reaping the rewards, Levi's stayed put in department stores and it cost the company dearly; during the ’90s and 2000s, Levi's attachment to tradition cost the brand thousands of jobs, billions of dollars and the ever-important “cool factor” with teenagers.

Unfortunately for other brands, Levi's solution to its problems for much of the 2000s was to sue—everyone. Starting in 2001, the brand brought hundreds of lawsuits against competitors, from Von Dutch to Rock & Republic to Jelessy Jeans to many of the small Japanese reproduction brands, such as Sugar Cane, that ushered in the Americana craze of the late 2000s. Levi's even had a forty-person team of denim detectives scouring boutiques and department stores across the world for copycats.

Only starting in 2010 did Levi's seem to realize that innovation was the solution; that same year, the brand introduced its Curve ID jeans for women, a range of three distinct cuts that fit a far wider variety of women’s body types than Levi's (or any other brand’s) previous offerings. In developing its new fit system, Levi's studied over 60,000 body scans and interviewed women of various builds from around the world. 2011 was an even bigger year for Levi's: the brand brought on Chip Bergh, its current President and CEO, introduced its Water<Less collection, which reduces water consumption by up to 96 percent during the production process, and debuted its Commuter line, featuring everyday performance products designed for urban cyclists. In 2013, the brand moved its innovation center from Corlu, Turkey to its home base in San Francisco, rechristening it the Eureka Innovation Lab. According to the article, “Does Levi Strauss still fit America?” in the October 6, 2014 issue of Fortune, the Eureka Innovation Lab’s “team of 30 technicians work on prototypes day in and out,” and “can turn out roughly 30 prototypes a week, taking a product from idea to design in less than 24 hours.”

Levi's (re)dedication to innovation seems to be working on multiple levels. The brand already produces about 25 percent of its products using Water<Less techniques and hopes to have that number up to 80 percent by 2020. In addition, Levi's seems to have regained much of its social capital with teens and tastemakers as indicated by its score with millennials in the recent Google-backed study, “It’s Lit: A Guide to What Teens Think Is Cool.” The brand’s newest project looks back to its 1974 Denim Art Contest by enlisting 50 “influencers” from around the world—including Virgil Abloh, Karlie Kloss, Chance the Rapper and Solange Knowles—to customize its Type III Denim jacket in honor of the product’s 50th anniversary. Considering denim’s revered place in the canon of American clothing, Levi's should be on its way back to its glory days, as long as the brand continues to remember that innovation is what made its products special in the first place.