In early August 1858, a submarine telegraph cable was laid between Valentia Island, Ireland, and Trinity Bay, Newfoundland. It enabled near-instant communication between Europe and North America for the first time, replacing messages that previously took days or weeks by ship. This success created huge public interest and proved that long undersea links were possible.
On August 16, 1858, the new cable carried high-profile inaugural traffic, demonstrating it could deliver real messages across the Atlantic. These ceremonial messages helped turn an engineering experiment into an international communication milestone. However, the cable’s performance was fragile, showing early limits of materials and testing methods.
By October 20, 1858, the first transatlantic cable had stopped working. Technical weaknesses—along with damaging operating practices such as using very high voltages—contributed to the failure. Even so, the project taught engineers what needed to change in cable design, manufacturing, and operation.
In 1865, engineers tried again using the massive steamship Great Eastern to lay a new cable from Ireland toward Newfoundland. The cable snapped mid-ocean and was lost, showing how difficult deep-ocean cable handling and recovery still were. The setback pushed improvements in equipment, procedures, and planning for the next attempt.
On July 27, 1866, a new cable-laying voyage reached Heart’s Content, Newfoundland, successfully completing a working telegraph link from Ireland. Unlike the 1858 cable, this connection proved durable enough for continuing service. It marked the start of reliable, long-term transatlantic submarine communications.
On September 25, 1956, TAT-1 began service as the first submarine telephone cable across the Atlantic, linking Scotland and Newfoundland. It carried dozens of simultaneous phone calls—far clearer and more reliable than long-distance shortwave radio. This shifted transatlantic communication from telegraphy toward real-time voice calls.
In September 1959, TAT-2 opened for service, extending high-quality transatlantic telephony to additional European networks through France. Adding another system increased capacity and reduced reliance on a single route. It also showed how quickly demand for transatlantic voice traffic was growing.
In 1963, TAT-3 connected Tuckerton, New Jersey, to Widemouth Bay, England, providing another major U.S.–U.K. transatlantic telephone route. Building multiple cables improved resilience if one line failed and helped meet rising demand. The system reflects the expansion phase of analog coaxial submarine telephony.
In 1970, TAT-5 entered service between Rhode Island and Spain, with an extension to Italy known as MAT-1. Routing through southern Europe broadened landing points and connectivity options. It also underscored that submarine cables were becoming a strategic, high-traffic part of international telecommunications.
In 1976, TAT-6 began operation between Rhode Island and France with far higher bandwidth than earlier cables. It supported thousands of telephone circuits, reflecting major improvements in analog coaxial design and repeaters (signal-boosting devices along the cable). This was a late peak for copper-based transatlantic systems before fiber optics took over.
On December 14, 1988, TAT-8 entered service as the first fiber-optic transatlantic cable, linking the United States, the United Kingdom, and France. Fiber optics carried much more data than copper coaxial cable and could be upgraded more effectively over time. This shift was a key step toward the modern internet-era backbone of high-capacity undersea networks.
In May 1989, PTAT-1 was turned on as the first privately financed transatlantic fiber-optic cable. It helped break older monopoly-style control over some international routes and encouraged more competition and investment. The result was faster growth in transatlantic capacity during the late 1980s and 1990s.
In December 1999, the Columbus-III transatlantic cable entered service, linking the U.S. to Portugal, Spain, and Italy. It reflects how transatlantic systems evolved into multi-landing networks built by large consortia, designed for rapid capacity growth. By the end of the 1990s, fiber cables like this became core infrastructure for global internet and data traffic.
Transatlantic Cables: Telegraph to Fiber (1858–2000)