High Quality Content by WIKIPEDIA articles! The Australian Overland Telegraph Line was a 3200 km telegraph line that connected Darwin with Port Augusta in South Australia. Completed in 1872 the Overland Telegraph Line allowed fast communication between Australia and the rest of the world. An additional section was added in 1877 with the completion of the Western Australian section of the line. It was one of the great engineering feats of 19th century Australia and probably the most significant milestone in Australia`s telegraphic history.