The last spike at Promontory
The first transcontinental railway across the United States was built from both ends. The Central Pacific started in Sacramento and worked east over the Sierra Nevada, using thousands of Chinese labourers, many of whom did the most dangerous work of blasting and tunnelling. The Union Pacific started in Nebraska and worked west across the plains, with crews that included many Irish immigrants and veterans of the Civil War.
The two lines met at Promontory Summit in the Utah Territory. On 10 May 1869 a ceremonial last spike, made of gold, was set into a laurel-wood tie. It was not actually driven in: it was a symbol, and it was replaced by an ordinary iron spike for the working railway. The telegraph wires had been connected to the spike and the hammer so that the news could go out at the moment of the blow, and in several cities bells were rung and cannon fired.
Seven days instead of six months
Before the railway, a journey from New York to San Francisco took months by wagon or by sea around Cape Horn or via Panama. Afterwards it took about a week. The line brought settlers, goods and markets to the West, and it also displaced the peoples who lived on the plains, whose land it crossed. The golden spike itself is kept at Stanford University.