On 10 May 1869 from Promontory Summit northwest of Ogden, Utah, a single telegraphed word, "done," signaled to the nation the completion of the first transcontinental railroad. Railroad crews of the Union Pacific, 8,000 to 10,000 Irish, German, and Italian immigrants, had pushed west from Omaha, Nebraska. At Promontory they met crews of the Central Pacific, which had included over 10,000 Chinese laborers, who had built the line east from Sacramento, California.

Actually, the construction crews built several miles of track parallel to each other. The federal legislation chartering the transcontinental project had not provided that the tracks join. There was nothing to prevent each line from continuing to build and thus increase the subsidies it might receive from the federal government. Therefore, Congress acted to set the meeting point at Promontory.

The ceremony that day to mark the completion of the last set of ties and spikes was somewhat disorganized. The crowd pressed so close to the engines that reporters could not see or hear much of what was actually said, which accounts for many discrepancies in the various accounts.