Hip Hip Hooray! The opening of the first transatlantic cable was celebrated with a wide range of souvenirs, including watch fobs, earrings, pendants, charms, letter openers, candlesticks, walking-stick toppers, and tabletop displays. Photo: Division of Work & Industry/National Museum of American History/Smithsonian Institution

On 16 August 1858, Queen Victoria and U.S. president James Buchanan exchanged telegraphic pleasantries, inaugurating the first transatlantic cable connecting British North America to Ireland . It wasn’t exactly instant messaging : The queen’s 98-word greeting of goodwill took almost 16 hours to send through the 3,200-kilometer cable. Still, compared to packet steamships, which could take 10 days to cross the Atlantic, the cable promised a tremendous improvement in speed for urgent communications.

This milestone in telegraphy had been a long time coming. Samuel Morse first suggested linking the two continents in 1840, and various attempts were made over the ensuing years.…