Pre-voting opinion polls gave the "No" campaign - those in favour of remaining in the United Kingdom - a slight edge. Hundreds of thousands of people were still making up their minds as polling stations opened, but as the day wore on, the British currency and major share prices rose on expectations there would not be a split.
Tennis star Andy Murray sent a powerful last-minute message in support of the pro-independence "Yes" vote, tweeting "Let's do this" after months of silence on his views. Many people see the choice as one of "hearts or heads" - whether emotional stirrings and yearnings would outweigh pragmatic concerns over the risks and uncertainty that an independent state would face.
"I've waited all my life for this," said the first voter in Edinburgh's Waverley Court, a businessman who gave only his first name, Ron. "It's time to break with England. 'Yes' to independence." As he spoke, a couple of workers hurrying by in the morning mist and drizzle shouted "Vote No!"" Those opposed to independence say a split could slow economic growth, affect the United Kingdom's defence capability, threaten the unity of other countries and tip the balance in favour of people who want Britain to leave the European Union.