Question: where did the western and eastern lines of railroad finally meet
Answer: The rails of the `` First Transcontinental Railroad '' were joined on May 10 , 1869 , with the ceremonial driving of the `` Last Spike '' at Promontory Summit , Utah , after track was laid over a 2,826 km ( 1,756 mi ) gap between Sacramento and Omaha , Nebraska / Council Bluffs , Iowa in six years by the Union Pacific Railroad and Central Pacific Railroad .