The standard gauge Kansas Pacific Railroad, reached Denver from Sheridan, KS on August 15th, 1870. The Denver Pacific Railrad (also standard gauge) reached Denver from Cheyenne, WY on August 22, 1870. The Denver and Rio Grande Railroad was created by Palmer, General William Jackson (formerly treasurer and head of construction for the Kansas and Pacific Railroad). First spike was driven July 28th, 1871. Line was completed to Colorado Springs on October 21st, 1871. Line was extended from Colorado Springs to Pueblo on June 15th, 1871, and from there to Labran (later Florence) on November 1st, 1871. The Silver Panic of 1873 halted further construction (except for a short line to Canon City) until 1876.