In the 1850s, the idea of a transcontinental railroad seemed as distant as a mission to Mars. The distance was staggering - nearly 1,900 miles from Council Bluffs, Iowa to San Francisco Bay. The obstacles were worse: the Sierra Nevada's granite walls, the alkali deserts of Nevada and Utah, the Rockies, the hostile Plains tribes, and a political system so divided that Southern and Northern congressmen couldn't agree on a route. Asa Whitney lobbied for years, printed maps and pamphlets at his own expense, and led expeditions to survey possible routes. The Pacific Railroad Surveys of 1853-1855 mapped alternatives but couldn't bridge the political divide. Only the Civil War's removal of Southern opposition finally broke the deadlock.

The Pacific Railroad Acts of 1862 and 1864 made the impossible merely improbable. The federal government offered loans based on terrain: $16,000 per mile on flat ground, $32,000 through foothills, $48,000 across mountains. Add massive land grants - alternating sections along the entire route - and suddenly there was money to be made. The Central Pacific would build east from Sacramento. The Union Pacific would build west from Omaha. With no set meeting point, the faster they built, the more money they collected. The race was on.

Two vast labor forces attacked the continent from opposite ends. The Union Pacific employed thousands of discharged Civil War veterans and Irish immigrants, using their military experience building truss bridges and laying track under fire. The Central Pacific, struggling to find workers in gold-rush California, turned to Chinese immigrants - eventually employing over 10,000 men who carved the railroad's path through the Sierra Nevada with picks, shovels, and black powder. They hung from baskets on cliff faces, drilled tunnels through granite by hand, and died by the hundreds in avalanches and explosions. Their wages were lower than white workers'. Their contribution was immense.

Theodore Judah surveyed the Central Pacific's route through the Sierra Nevada before dying of yellow fever, never seeing his vision completed. His successors faced the Summit Tunnel - 1,659 feet through solid granite at 7,000 feet elevation. Workers advanced eight inches per day using hand drills and black powder, later nitroglycerin. Winter storms buried work camps under forty feet of snow. Men lived in tunnels carved beneath the drifts. Avalanches swept entire crews down mountainsides. Yet foot by foot, the railroad advanced. When the Summit Tunnel finally broke through, the hard work was just beginning - there were still fifteen tunnels to go before the tracks reached Nevada.

By spring 1869, the competing railroads were laying track at impossible speeds across Utah Territory, sometimes building parallel grades within sight of each other, neither willing to stop. Congress finally mandated a meeting point: Promontory Summit, north of the Great Salt Lake. On May 10, dignitaries gathered for the ceremony. Stanford's famous miss with the silver hammer has become legend, but the golden spike was always ceremonial - too soft to actually drive. What mattered was the telegraph signal that flashed across the nation: the work of a generation was complete. Six days now separated the coasts instead of six months. The West was open.