Americans were on pins and needles exactly 150 years ago. They gathered at train stations and outside newspaper offices eagerly awaiting word that a modern marvel was now a reality. They’d followed developments closely as two railroads raced each other to complete the Victorian Era’s greatest accomplishment — the world’s first transcontinental railroad. On May 10, 1869 it was about to be finished.

When the breaking news from out West finally hit thousands of telegraph offices around the country, it was wrong. Here’s what happened.