While long-distance lines had been installed between cities since the late 1800s, this was the first coast-to-coast call, made possible by 4,750 miles of connected telephone wire. The final connection was made on the Nevada and Utah state line on June 17, 1914, and AT&T president Theodore Vail successfully transmitted his voice across the country in July 1914.

To reveal the new accomplishment, Bell performed a phone call six months later from fifteenth floor of the Telephone Building at 15 Dey Street in Lower Manhattan to San Francisco, where the Panama–Pacific International Exposition was taking place. With Bell in New York and his partner Thomas Watson in San Francisco, they proceeded to reenact the same exchange they had first performed 38 years earlier when perfecting the telephone by communicating between floors of a Boston boarding house, except this time when Bell called out for Watson to "come here", Watson joked that it would take a week for him to arrive.

The signal was a single-line open loop between New York, Washington D.C., Jekyll Island in Georgia, and Boston, allowing many participants during the call, including President Woodrow Wilson from D.C. and AT&T president Theodore Vail from Jekyll Island, Georgia where he was recovering from a leg injury. The great distance was made possible by vacuum tubes called "audions" that amplified the signal as it traveled across the country, and approximately 1,500 AT&T employees were stationed along the loop of wire on the day of the demonstration, standing ready to repair any damage.

After the debut, AT&T offered the transcontinental telephone line for business use, charging $20.70 for the first three minutes, equivalent to a staggering $515 in 2018, since the one nationwide phone line could only carry one call at a time.