On October 31, 1963, American television impresario Ed Sullivan, waiting for a flight at London's Heathrow Airport, happens to witness the pandemonium of Beatlemania—a pop-culture fever then raging in the U.K. and rapidly spreading across the European continent. Thinking the mass hysteria must be for a member for the British royal family, he was told it was actually for a popular rock 'n' roll band called the Beatles. His response: "Who the hell are the Beatles?"

Sullivan's chance encounter with throngs of teenagers screaming and fainting for four mop-topped Liverpudlians would leave a lasting impression—and ultimately play a pivotal role in making the "British Invasion" of America possible.

In the fall of 1963, when artists like Bobby Vinton, Dion and Jimmy Gilmer and the Fireballs sat atop the U.S. pop charts, John, Paul, George and Ringo could have walked through New York's LaGuardia Airport completely unnoticed. But at Heathrow, where they were just returning from a hugely successful tour of Scandinavia, more than 1,000 fans waited in the cold rain to raucously welcome them home. Sullivan, just completing a talent-scouting tour of Europe for his hugely popular variety show, found himself in the proverbial right place at the right time.

It wasn’t for lack of trying that the Beatles were still unknown in the United States. Their manager Brian Epstein had tried and failed repeatedly to convince Capitol Records, the American arm of their British label EMI, to release the singles that had already taken Europe by storm. Convinced that the Merseybeat sound wouldn’t translate across the Atlantic, Capitol declined to release “Please Please Me,” “From Me to You” and “She Loves You,” allowing all three to be released on the minor American labels Vee-Jay and Swan and to languish on the pop charts without any promotion. Desperate to crack the American market, John Lennon and Paul McCartney wrote a song explicitly tailored to the American market and recorded it just two weeks before their fateful indirect encounter with Ed Sullivan. That song was “I Want to Hold Your Hand.”

Following his return to the United States, Sullivan—who had seen similar teen mania around a musician named Elvis Presley—had his staff make inquiries about the Beatles, prompting the group's manager Brian Epstein to travel to New York to open negotiations. And in what surely must rank as one of the greatest one-two punches in the history of professional talent-management, Epstein convinced "The Ed Sullivan Show" to have the Beatles as headliners for three appearances rather than as a one-time, mid-show novelty act. He then leveraged that contract into an agreement by Capitol Records to release “I Want To Hold Your Hand” in the United States and back it with a $40,000 promotional campaign.

As a result of the chance airport encounter, and of Brian Epstein’s subsequent coup in New York, the Beatles would arrive in America on February 7, 1964, with a #1 record already to their credit. The historic "Ed Sullivan Show" appearances that followed would lead to five more in the next 12 months.