Construction of the Transcontinental Railroad across the United States was one of the most significant historic events of the 1800s. Built almost exclusively with manual labor and hand tools, the cross-country railroad took only four years to construct. Large numbers of workers were needed to survey and grade the bed, and lay down the ties and rails. Union Pacific chief engineer General Grenville Dodge used a geological feature called the Gangplank, located 15 miles to the east, as an easy grade to route the railroad across the Laramie Mountains. Construction of the Transcontinental Railroad led to settlements sprouting up along its path, an increase in population, and the creation of the Wyoming Territory. The driving of the golden spike at Promontory Summit in Utah on May 10, 1869 ushered in a new era of America. As author T.H. Watkins wrote, once the rails were joined at Promontory, Americans began for the first time truly to think of themselves as a continental nation. With the completion of the railroad, passengers and freight were able to make the journey across America in a matter of days instead of the months it had taken by wagon or ship. Sherman, Wyoming, existed as a railroad town about a quarter mile from the monument between 1867 and 1901. Sherman had a Wells Fargo express office, a newspaper, a clothing store, two false-fronted hotels, and a bar. The town's timber mill produced thousands of ties for the railroad. In time Union Pacific moved the tracks three miles south to a lower elevation with less snow, bypassing the dangerous single-track bridge at Dale Creek, and Sherman soon became a ghost town. The bridge at Dale Creek, about two miles west of Sherman, presented Union Pacific construction engineers with one of their most difficult challenges. At 706 feet in length, it was the longest and highest bridge along the Union Pacific Railroad. The wooden trestle stood 125 feet above the valley floor and swayed dramatically in the wind as trains crossed. Engineers had to slow a train to four mph before crossing to prevent the strong Wyoming winds from blowing empty boxcars off the bridge and into the rocky ravine below.