William Wrigley Jr. was born in Philadelphia, Pennsylvania, on September 30, 1861, to William and Mary Wrigley. He was the eldest of nine children. Wrigley had the reputation of being a defiant child and got kicked out of school several times before he ran away to New York City at the age of eleven. While in New York, he found a job as a newspaper boy and spent three months living on the streets before he finally returned home when the weather got too cold. His father put him back in school, but he was soon expelled for pulling a prank in which he threw a pie at the school's nameplate over the main entrance.

His father, a soap manufacturer, had finally given up on his son's education and decided to put him to work in his soap factory doing the most strenuous job. For ten hours a day, Wrigley stirred the soap vats with a large wooden paddle. By the age of 13, Wrigley found his way out of the factory and decided to be a salesman for his father. He acquired a horse and wagon and ventured across Pennsylvania and New York selling soap. During this time, Wrigley's talents for selling became apparent. According to Nathan Aaseng in his book Business Builders in Sweets and Treats, "From the beginning, it was clear William had two of the key qualities for salesmanship: personality and persistence. He made friends wherever he went. No matter how desperate he was for a sale, he remained unfailingly polite and never argued with a customer. Over time, the goodwill he generated turned into sales." Wrigley was a gifted salesman, but he lost interest in his job quickly and hopped a train west. After losing his train ticket in Kansas City, he returned home to Pennsylvania and continued to work in the factory.

In 1885, Wrigley married Ada E. Foote, and they had two children, Dorothy and Philip. After getting married, he decided to head to Chicago in 1891 to sell soap and baking powder under the label of his own business, the William Wrigley Jr. Company. He only had $32 in his pocket at the time. In order to get his business off to a good start, Wrigley came up with a marketing plan in which he offered premiums with every single sale. He then raised the price of his product and offerred a free item along with it. He started by offering red umbrellas, then tried cookbooks and toiletries, but the product he found that was most attractive to customers was chewing gum. When Wrigley realized how popular chewing gum was, he dropped his soap and baking powder products and began selling two brands of Zeno chewing gum. Wrigley explained his success in sales when he said, "You must have a good product in the first place and something people want. Explain to folks plainly and sincerely what you have to sell, do it in as few words as possible — and keep everlastingly coming at them."

By 1893, Wrigley finally developed his own two types of chewing gum: Spearmint and Juicy Fruit. Since he was a persistent business man, he spent 187 nights in railroad cars crossing the country to promote his product. He kept up with the premiums, giving away cash registers and coffee makers to store owners who bought his product. Wrigley also found that many times customers bought gum on a whim, and therefore he came up with the strategy of placing gum display cases next to registers to help promote business.

In 1907, when a depression hit the American economy, Wrigley seemed untroubled. It was during this time that he became a pioneer in the advertising industry. While other gum manufacturers cut revenues and expenses to make it through the depression, Wrigley took out a massive loan of almost $250,000 to launch an ad campaign. His approach to advertising is explained in his slogan of "tell 'em quick, and tell 'em often." Luckily for him, this risky gamble paid off and business kept up while competitor sales sat still. In just one year, sales went from $170,000 to a staggering $3 million. Wrigley took his advertising schemes even further when he gathered addresses from all published telephone books and sent free packs of gum to over 1.5 million American homes in 1915 and then to almost 7 million homes in 1919. He had finally made a name for himself, and he was now considered one of the most successful business leaders in America.

It was also around this time that Wrigley's interests grew in matters other than chewing gum. In 1914, he bought a mansion in Pasadena, California, and that same year he had the Wrigley Tower in Chicago named after him, as well as a local city baseball stadium. He became very interested in baseball and soon began giving money to the Chicago Cubs franchise. By 1920, he had total control of the Cubs and even bought out a Los Angeles franchise. He then purchased a minor league team in Reading, Pennsylvania, and he founded the "farm system," which major league teams used to train players and get them ready for the pros. In 1926, the Chicago Cubs's ivy-covered brick stadium was named Wrigley Field and is widely known as "baseball's most beautiful venue."

Wrigley also bought into an expensive piece of real estate. In 1919, he purchased Santa Catalina Island off the coast of Los Angeles, California, and he made it into a vacation paradise. He built 2,500 "bungalettes," which accommodated 2 to 3 individuals, and he filled the island with gardens, aviaries, and recreation. Wrigley's baseball team also used Catalina Island as a spring training site. The island became a hot spot for Hollywood stars and was even used as the setting for some motion pictures. Today, his legacy lives on through this island, which he had protected for future generations to enjoy.

After spending most of the 1920s in California, Wrigley moved to Arizona in 1929, and he built another mansion. Shortly thereafter, he passed away in Phoenix, Arizona, on January 26, 1932. He was laid to rest on his paradise home in Santa Catalina Island in the center of a botanical garden. Today, William Wrigley's company still continues to have great success, and he is known as one of America's most accomplished entrepreneurs. As Edwin Wildman described him in Famous Leaders of Industry, "His moral and physical courage, his steady perseverance and unfailing good humor and optimism, his love of hard work and good-fashioned American grit and gumption, his faith in his fellow man — all these qualities are strong in William Wrigley, Jr. Because of them he succeeded, where countless failed."