The development of the main trunk railway line through the King Country from the 1880s was a crucial event in the region's history. It signalled the beginning of the end of the region's independence from the government, and opened the way for European settlement. On 6 November 1908 Prime Minister Joseph Ward drove the last railway spike into the land in a symbolic gesture which marked the joining of the line from the south with that from the north, and the completion of the line between Wellington and Auckland. In fact, the line was not quite finished – rails were still being laid across the nearby Manganuioteao viaduct during the ceremony.

Ward was presented with this sterling-silver spike to mark the occasion. There is a last-spike monument on State Highway 4, between Erua and Pōkākā.