The Answer:

On Jan. 25, 1915, the first official transcontinental phone call was made between Alexander Graham Bell in New York City and Thomas A. Watson in San Francisco. Using a replica of the first telephone, Bell said "Mr. Watson—come here. I want you!" This was the same request that had been been transmitted between the duo in the first telephone conversation, on March 10, 1876.

For more information, check out our Inventions and Discoveries section.

—The Editors