It has been 243 years since the Declaration of Independence has been signed. It was signed nearly two and a half centuries ago, that's a very long time. The Declaration of Independence was written 243 years ago. At the time, the USA only had 13 states, it would continue to grow. We celebrate the signing of the Declaration of Independence on the 4th of July. People shoot off fireworks because July 4, 1776 was a day that Americans glorify.