Spam luncheon meat was introduced by Hormel Foods in 1937. The previous year, the company had devised a recipe for a canned loaf of spiced ham. Because this product was quickly copied by imitators, though, Jay C. Hormel was determined to give it a distinctive name that would set it apart from competitors. He offered a $100 prize, and the winning name was submitted by Kenneth Daigneau, the brother of a Hormel vice president.

In 1941, the U.S. Congress passed the Lend-Lease Act, providing for aid to Allied forces. Soon many millions of cans of Spam were being shipped to Great Britain and Russia. Before long, the ubiquitous luncheon meat had become notorious as "the ham that didn't pass its physical" and "a meatball without basic training." Nevertheless the product played an important role in helping sustain Allied forces during World War II.

After the war, Spam remained a popular food. By 1994, the five-billionth can of the luncheon meat had been produced. Today about 150 million cans of Spam are sold worldwide every year. In the United States alone, a can of Spam is eaten about every four seconds. Yet despite the product's proven popularity, it continues to be the butt of jokes. Internet users have even adopted the term "spam" to refer to electronic junk mail and junk newsgroup postings.