Newfoundland's geographic position as North America's nearest landfall to Europe has given it a prominent role in the fields of transportation and communications. Since its discovery by John Cabot in 1497, Newfoundland has been the guardian or sentinel of the North American continent.

The history of communications in Newfoundland has been fascinating, and there have been many significant firsts. Atlantic Sentinel covers the period from the mid-1800s to the late 1990s. During this era, Newfoundland's first telegraph system (1851) was installed, the first transatlantic cable (1858) was laid, the first transatlantic radio message (1901) was received, the first off-island telephone message (1939) was made, the first transatlantic telephone cable (1956) went into service, and the first off-island digital optical fibre system (1991) was installed.