<P> The line was constructed primarily by Irish labor who had learned their craft during the recent Civil War . The two lines were joined together at Promontory Summit , Utah , 53 miles ( 85 km ) west of Ogden on May 10 , 1869 , hence creating the first transcontinental railroad in North America . Under the guidance of its dominant stockholder Dr. Thomas Clark Durant , the namesake of the city of Durant , Iowa , the first rails were laid in Omaha . </P>
who directed the union pacific railroad 's movement west
its dominant stockholder Dr. Thomas Clark Durant