The first telegraph cable across the Atlantic was completed on 5 August 1858, and Queen Victoria and President Buchanan exchanged congratulations over it later that month. The signal was faint from the start, and an engineer raised the voltage to force it through. The insulation gave out in September, and it took another eight years to lay a cable that lasted.
Why this oneThe first one worked, briefly, and was killed by the attempt to make it work better.