<P> A transatlantic telegraph cable is an undersea cable running under the Atlantic Ocean used for telegraph communications . The first was laid across the floor of the Atlantic from Telegraph Field, Foilhommerum Bay, Valentia Island in western Ireland to Heart's Content in eastern Newfoundland . The first communications occurred August 16, 1858, reducing the communication time between North America and Europe from ten days--the time it took to deliver a message by ship--to only 17 hours . Transatlantic telegraph cables have been replaced by transatlantic telecommunications cables . </P> <P> In the 1840s and 1850s several individuals proposed or advocated construction of a telegraph cable across the Atlantic Ocean, including Edward Thornton and Alonzo Jackman . Cyrus West Field and the Atlantic Telegraph Company were behind the construction of the first transatlantic telegraph cable . The project began in 1854 and was completed in 1858 . The cable functioned for only three weeks, but it was the first such project to yield practical results . The first official telegram to pass between two continents was a letter of congratulations from Queen Victoria of the United Kingdom to the President of the United States James Buchanan on August 16 . Signal quality declined rapidly, slowing transmission to an almost unusable speed . The cable was destroyed the following month when Wildman Whitehouse applied excessive voltage to it while trying to achieve faster operation . It has been argued that the faulty manufacture, storage and handling of the 1858 cable would have led to premature failure in any case . The cable's rapid failure undermined public and investor confidence and delayed efforts to restore a connection . A second attempt was undertaken in 1865 with much - improved material and, following some setbacks, a connection was completed and put into service on July 28, 1866 . This cable proved more durable . </P>

What year was atlantic cable put on the bottom of the ocean floor