The 1964-1965 World’s Fair featured more than 140 pavilions, 110 restaurants and some 45 corporate exhibits — and attracted more than 51 million visitors. Spanning 646 acres in Flushing Meadows Park in Queens, New York, the event was considered a pinnacle of mid-20th-century American culture and technology. It showcased products that would advance the transportation and consumer electronics markets in a way that would never be repeated at future World’s Fairs.

IBM’s participation was practically a given, considering the event’s technological orientation and the proximity to corporate headquarters. The company had two primary goals for its massive presence: to increase demand for computer use among existing and potential corporate clients, and to broaden the public’s comfort with technology via creative marketing of the company’s products.

Occupying a little more than an acre, the IBM Pavilion was three years in the making. The installation entailed a covered-garden motif with exhibits distributed beneath a grove of 45 man-made, 32-foot-tall steel trees. It comprised six sections: the Information Machine, a 90-foot-tall main theater with multiple screens; smaller theaters where puppets explained how data-processing systems work; a computer applications area; the Probability Machine; the Scholar’s Walk, which displayed detailed explanations of computer operations; and a 4,500-square-foot administration building. The company organized its presentations to allow visitors to inspect, and in some cases sample, many of IBM’s tangible contributions to solving problems for industry and society.

The Ovoid Theater, a steel-and-concrete structure called the “egg” because of its shape, which was meant to evoke the IBM Selectric “golf ball” mechanism, sat atop the exhibition. Every 15 minutes, some 500 visitors would enter by stepping onto the “People Wall,” 12 tiers of seats that were hydraulically hoisted into the theater. In a 12-minute presentation projected onto 22 screens, a host in white tie and tails descended by wire from an opening in the ceiling and guided viewers through a presentation designed to demystify computational workings.

“The IBM show is a sensation,” New York Times critic Bosley Crowther wrote. Another Times writer, Walter Carlson, captured the scope of the experience for an imagined viewer: “He finds himself in the middle of an auto race, in a wind tunnel, out in the country, and even inside the mind of a woman planning a party guest list.”

The renowned architecture magazine Domus described the theater in a way that nearly anticipated 21st century communications paradigms. “The suspended Ovoid Theater may actually be an invention which goes far beyond the occasion of the Fair. Replicas in the different countries will make it possible to give people — at the same moment — the same up-to-date information, without obliging them to converge from far away distances at one point in the world.”

All of the exhibits, which were designed by the Eames Office, were derived from Mathematica, an interactive exhibition that IBM had commissioned in 1961 for a new wing of the California Museum of Science and Industry. Below the theater, some 100 IBM employees answered visitor questions and orchestrated puppet shows to lighten the education agenda. At one of the smaller theaters, Sherlock Holmes employed binary logic to solve conundrums such as “The Case of the Elusive Train.”

In the highly popular Probability Machine exhibit, a tall, glass-enclosed device demonstrated the calculation of probability curves, repeating its experiment in 14-to-18-minute cycles. Roughly 17,000 polyethylene balls would drop into one of 21 chutes at the bottom of the contraption. In a demonstration of normal distribution, commonly known as the bell curve, the chutes would fill to approximately the same levels each time.

In the computer applications area, IBM staffers presented a display of Russian-to-English language translation and character recognition that was mind-boggling for its time. Texts were transmitted over telephone lines from two IBM 1050 data communications systems in the pavilion to a facility in Kingston, New York, and returned in near real time. The demonstration drew attention to foundational technological developments that continue to be used in translation platforms and applications to this day.

In the character-recognition exhibit, visitors would handwrite the numerals of any date from the previous 100 years onto an IBM card, which was placed in a reading device. The machine matched the handwritten figures to dates stored on an IBM 1311 Disk Storage Drive and produced a headline from the most historically significant story from that day. Controlled by an IBM 1460 system, it printed information at the rate of 1,100 lines per minute.

The so-called Typewriter Bar was a source of astonishment. A circular arrangement of 10 stations gave visitors the opportunity to type out postcards on IBM’s state-of-the-art Selectric machines. Attendees marveled at the way Selectric keyboards were capable of typing characters with the bare touch of a fingertip — a huge advance over the clunky manual machines that ruled the day. Ultimately, the IBM Pavilion was the second most popular stop at the fair after the Futurama exhibit from The General Motors Corporation.

In summarizing the event’s ultimate impact, Dag Spicer, a senior curator at the Computer History Museum, recalled the importance that exposure and education have always played in IBM’s marketing efforts. On the one hand, the company simply sought to increase demand for its products. “But,” he added, “events like the 1964 World’s Fair were a longer term bet: that by introducing computers in the informal, festival-like atmosphere of a fair, the computer would be seen as a force for positive change, rather than the popular notion of computers as mysterious and, possibly, dangerous.”

Exhibit designers Charles and Ray Eames and Eero Saarinen issued a joint statement that captured their mission and mandate. The objective “was to show that the methods used by computers in the solution of even the most complicated problems are merely elaborations of simple, human-scale techniques which we all use daily,” they said. “By inviting the visitor to participate in a series of experiences, we could communicate ideas directly. We could make him feel, as well as understand, that the role of the computer is not only less mysterious but much closer to his own life experience than he may have thought and that beneath the most apparent complexity there is always astonishingly simple and logical order.”