1915 – MP and SLIM&S 
      declare bankruptcy and are placed into receivership. WP goes into 
      receivership, followed by D&RGW. A year later, WP reorganizes. Gould loses 
      control of the railroad. 
      
      1917 – MP and SLIM&S are 
      reorganized and merged into the Missouri Pacific Railroad Company. 
      
      
      1921 – Discovery of the 
      Lincoln railroad car silver in a UP vault in Omaha leads to the founding 
      of the Union Pacific Historical Museum in the headquarters building. 
      1924 – MP gains control of 
      the New Orleans, Texas & Mexico Railroad and its subsidiaries. By 1929, MP 
      and NOT&M have added several other Texas and Louisiana railroads to their 
      empire.
      1928 – The 6.21 mile-long 
      Moffat Tunnel is completed in Colorado, allowing Denver & Salt Lake to 
      abandon its route over Rollins Pass and shorten its route by 22.84 miles.
      1930 – The Denver & Rio 
      Grande Western gains control of the Denver & Salt Lake. 
      1931 – WP completes 
      construction between Keddie and Bieber, CA on the Inside Gateway route. 
      This line, in conjunction with the Great Northern, competes with SP for 
      traffic to Oregon and California.
      1932 – SP gains control of 
      the St. Louis Southwestern Railway, commonly known as the Cotton Belt.
      1933 – MP declares 
      bankruptcy and is placed in trusteeship.
      1934 – The nation's first 
      streamliner, the M-10000, introduces luxury passenger service. The Denver 
      & Rio Grande Western completes the construction of the Dotsero cutoff, 
      connecting the D&RGW and D&SL main lines in central Colorado and opening a 
      direct route between Denver and Salt Lake City.
      1935 – Western Pacific goes 
      into receivership.
      1936 – UP opens the Sun 
      Valley Resort in Idaho, the country's first western ski resort. It 
      features the nation's first ski lift with chairs, invented by railroad 
      personnel in Omaha. C&NW, UP and SP jointly inaugurate the City of San 
      Francisco streamliner running between Chicago and Oakland.
      1937 – Diesel-electric 
      locomotives are introduced on the Missouri Pacific. 
      1939 – Cecil B. DeMille's 
      motion picture "Union Pacific" premieres in Omaha. 
      
      1941 – The largest steam 
      locomotive ever built, the Big Boy, goes into service on UP lines. This 
      same year, diesel power is introduced for freight service. 
      1944 – The last steam 
      engine built for the UP, number 844, is constructed.
      1945 – WP emerges from 
      reorganization.
      1949 – Blizzards strike 
      Nebraska and Wyoming, closing UP's main line for seven weeks. 
      
      1955 – Missouri Pacific 
      retires its last steam locomotive. 
      1956 – A 23-year 
      trusteeship, the longest in U.S. rail history, ends as MP is reorganized. 
      The Gulf Coast lines (NOTM, BSL&W, O&NW, NI&N, ISM&E, SLB&M, IGN, SAS, 
      SAUG, AB, SB&RGV, SL, H&BV, HNS) are absorbed into MP.
      1958 – UP acquires Spokane 
      International, giving UP a connection with Canadian Pacific Railway. 
      Litchfield & Madison is merged into Chicago and North Western. Steam 
      engines make their last runs on SP.
      1960 – UP targets Chicago, 
      Rock Island & Pacific as a merger partner, beginning one of the longest, 
      most bitterly contested merger proposals in railroad history. SP and Santa 
      Fe begin an attempt to acquire the WP. Minneapolis & St. Louis is merged 
      into C&NW.
      1961 – SP absorbs its Texas 
      & New Orleans subsidiary.
      1964 – Texas & Pacific 
      gains control of the Kansas, Oklahoma & Gulf and Midland Valley Railways. 
      The KO&G-MV partner, Oklahoma City-Ada-Atoka Railway, is sold to the 
      Atchison, Topeka & Santa Fe.
      1965 – The Pacific Electric 
      subsidiary is absorbed into SP.
      1966 – ICC rejects the 
      SP-AT&SF bid to acquire the WP.
      1967 – MP gains control of 
      the Chicago & Eastern Illinois Railroad. SP completes the 78-mile 
      Palmdale-Colton cutoff, allowing trains to bypass the Los Angeles basin.
      1968 – UP acquires the 
      Mount Hood Railroad. The Chicago Great Western is merged into C&NW. MP and 
      C&NW gain joint control of the Alton and Southern.
      1969 – The Union Pacific 
      Corporation is established as a holding company, with Union Pacific 
      Railroad as one of its operating companies. The Ft. Dodge, Des Moines & 
      Southern is leased by C&NW. MP sells the Evansville line (eastern side) of 
      C&EI to Louisville & Nashville, and the Chicago to Woodland junction 
      passes into joint MP-L&N ownership.
      1970 – Western Pacific's 
      California Zephyr vista dome passenger train makes its last run. D&RGW 
      loses the last vestige of its steam-powered narrow gauge empire when the 
      Chama, New Mexico to Durango, Colorado line is abandoned. Durango to 
      Silverton remains as a tourist attraction, while Chama to Antonito, 
      Colorado is sold for tourist train use.
      1971 – The National Rail 
      Passenger Service Act transfers most passenger service to Amtrak (America, 
      Travel and Track). Some railroads, notably the Denver & Rio Grande 
      Western, Southern, and Chicago, and Rock Island & Pacific hold out and 
      continue to operate their own trains.
      1974 – The ICC rules in 
      favor of the UP-CRI&P merger, but three months later UP terminates its 
      offer for the CRI&P, as the line is steadily declining. Rock Island falls 
      into receivership.
      1976 – The Railroad 
      Revitalization and Regulatory Reform (4R) Act calls for the restructuring 
      of bankrupt lines and makes $2.1 billion in repayable financing available 
      to northeastern and midwestern companies. The Chicago & Eastern Illinois 
      and Texas & Pacific subsidiaries are absorbed into MP; the parent 
      corporation, Mississippi River Corp., is renamed the Missouri Pacific 
      Corp.
      1977 – The first 
      double-stack car for container traffic is designed and tested by SP.
      1978 – Pacific Fruit 
      Express, jointly owned by SP and UP, is dissolved equally. It becomes the 
      SPFE and UPFE companies.
      1980 – The Union Pacific, 
      Missouri Pacific and Western Pacific railroads file merger applications 
      with the Interstate Commerce Commission. Chicago, Rock Island & Pacific 
      ceases operations. In the following years, many of its lines are sold to 
      other railroads, including MP, SSW and MKT. SSW acquires the Rock Island 
      "Tucumcari" line and gains access to Kansas City. The MKT subsidiary 
      Oklahoma, Kansas & Texas is created by purchasing Herington, KS to Dallas, 
      TX from CRI&P.
      1982 – The UP-MP-WP merger 
      is approved by ICC. As conditions of the merger, D&RGW gains trackage 
      rights from Pueblo to Kansas City and SP gains trackage rights from Kansas 
      City to St. Louis via MP. 
      1983 – D&RGW ceases 
      operation of its Denver-Salt Lake City Rio Grande Zephyr and joins Amtrak.
      1984 – UP and C&NW complete 
      a connector line to the Powder River coal basin fields in eastern Wyoming.
      1986 – C&NW purchases the 
      Kansas City-Minneapolis "Spine Line" from the Rock Island trustee after 
      fierce competition from the Soo Line. C&NW proceeds to abandon the 
      now-redundant ex-CGW line.
      1988 – UP acquires the 
      Missouri-Kansas-Texas Railroad, commonly known as the Katy. Rio Grande 
      Industries acquires the Southern Pacific Railroad. The D&RGW and SP 
      railroads are merged, retaining the SP name. 
      1989 – UP's Harriman 
      Dispatching Center opens in Omaha, centralizing all train dispatching in 
      one location. UP purchases 25% of Chicago & North Western stock, which is 
      held in a voting trust. SP gains access to Chicago with the purchase of 
      the St. Louis to Chicago line from the defunct Chicago, Missouri & 
      Western. SP sets up a SPCSL (SP-Chicago-St. Louis) subsidiary.
      1993 – Disastrous flooding 
      during the summer months strikes the midwestern states, causing millions 
      of dollars in damage to UP and other railroads' physical plants. Train 
      service is disrupted for several weeks throughout the region, as 
      floodwaters crest.
      1994 – UP gains minority 
      control of the C&NW following the ICC's approval of the voting control 
      granted by its stock holdings. UP makes an offer for the Atchison, Topeka 
      & Santa Fe in competition with Burlington Northern.
      1995 – UP merges with C&NW 
      after acquiring the remaining 75% of its stock. UP ends its attempts to 
      acquire the Santa Fe. The BN and AT&SF merge into the BNSF Corporation, 
      and SP gains significant trackage rights from BNSF as a merger concession. 
      On July 23, Union Pacific announces it will run a special passenger train 
      across major portions of the United States to carry the 1996 Centennial 
      Olympic Games flame to Atlanta. On August 3, UP and SP announce their 
      intent to merge. Union Pacific and Burlington Northern Santa Fe reach a 
      comprehensive agreement on September 27 to preserve and intensify rail 
      competition following the UP/SP merger. On November 30, Union Pacific 
      files its application with the Interstate Commerce Commission to acquire 
      Southern Pacific. The 50,000th coal train is operated out of Wyoming's 
      Powder River Basin on December 28, 12 years after UP operated the first 
      train over the newly constructed connector line on August 16, 1984.
      1996 – On January 19, plans 
      are announced of the intent to sell the 203-mile "Colony Line" in western 
      South Dakota and Wyoming to the Dakota, Minnesota and Eastern Railroad. 
      The 40-day journey of the Union Pacific 1996 Olympic Torch Relay Train 
      begins its run on April 26. The Surface Transportation Board votes to 
      approve the UP/SP merger on July 3. On July 27, Dick Davidson is elected 
      as Union Pacific Corporation COO, and Ron Burns is elected as Union 
      Pacific Railroad president. The Union Pacific-Southern Pacific merger 
      takes effect on September 11, forming the largest railroad in the U.S. Ron 
      Burns resigns as CEO and president of Union Pacific Railroad on November 
      6. Jerry Davis is named president and COO of the railroad. Dick Davidson, 
      president and COO of UP Corporation and chairman of UPRR, is named CEO of 
      the railroad. Dick Davidson is elected chairman and CEO of Union Pacific 
      Corporation on November 21, succeeding the retiring Drew Lewis.
      1997 – On January 1, the 
      Missouri Pacific Railroad legally merges into Union Pacific Railroad, with 
      UPRR remaining as the surviving corporation. The Feather River Canyon line 
      reopens on March 3, after massive flooding closed the line on January 2. 
      On May 2, the first major step in the UP/SP merger is taken with the 
      completion of the first of four cutovers to the computerized 
      Transportation Control System (TCS); the former Denver & Rio Grande 
      Western portion of the SP. The former SP headquarters building in San 
      Francisco is offered for sale on June 15. A joint safety team of UP 
      managers, union employees and Federal Railroad Administration 
      representatives is established to review safety across the UP system on 
      August 27. On September 3, UP and FRA unveiled a package of Safety 
      Assurance Compliance Process measures (SACP). Union Pacific files a 
      Service Recovery Plan with the Surface Transportation Board aimed at 
      eliminating congestion on October 1.
      1998 – UP and BNSF announce 
      that a joint regional dispatching center for Gulf Coast operations will be 
      opened in Spring, Texas on March 15. On April 2, work begins on restoring 
      17 miles of former Missouri-Kansas-Texas track in new Braunfels, Texas to 
      improve train movement between Ft. Worth and San Antonio. UP and BNSF 
      announce the sale of the jointly-owned Camas Prairie Railroad in Idaho to 
      a subsidiary of North American RailNet, Incorporated on April 17. On July 
      6, the sale of 12 miles of the Colorado Royal Gorge line to a tourist 
      railroad is announced. A new $70 million intermodal terminal opens at 
      Marion, Arkansas, 10 miles west of Memphis, Tennessee, on July 10. Ike 
      Evans is named president and COO, and Jerry Davis is named vice chairman 
      of Union Pacific Railroad, on September 15. A new $32 million diesel shop 
      is dedicated at Hinkle, Oregon on November 23, and a special train 
      dedicates the restoration of double track in western Iowa on December 1.
      1999 – Union Pacific 
      increases it's financial interest in Ferrocarril Mexicano (Ferromex) to 26 
      percent. UP and Burlington Northern Santa Fe agree to coordinated 
      dispatching operations covering Southern California, the Kansas City area 
      and the coal-rich Powder River Basin of Wyoming. It is the largest 
      railroad coordinated dispatching agreement in history. The rebuilt 
      classification yard in Roseville, Calif., is reopened and named after 
      retired UP Vice Chairman Jerry Davis. One of the largest railroad 
      construction projects in modern times, the rebuilding of the double track 
      main line and the addition of a third main track across Central Nebraska 
      is completed. The segment is the busiest freight corridor in North 
      America. An agreement is reached with the Electro-Motive Division of 
      General Motors Corporation to lease 1,000 new SD70M locomotives, the 
      largest single unit order in history and the beginning of an extensive 
      locomotive replacement program.
      2000 – A 105-mile 
      double-track project is completed between Gibbon, Neb. and Marysville, 
      Kan. A new auto unloading facility is opened in Council Bluffs, Iowa. 
      Another new auto facility also is opened in Centreville, Ill., serving the 
      St. Louis area.
      2001 – Union Pacific 
      tightens security across its system following terrorist attacks in New 
      York City and against the Pentagon in Arlington, Va. Union Pacific begins 
      adding large American flag decals to the sides of its locomotives.
 
      Union Pacific named railroad supplier to the 2002 
      Olympic Winter Games. 
      2002 – Union Pacific 
      Corporation celebrates construction of its new 19-story headquarters 
      building in Omaha. The building is scheduled to open in 2004. The sale of 
      track and land between San Jose and Fremont, Calif. to the Santa Clara 
      Valley Transportation Authority is announced. The company also announces 
      the sale of land and track to the Utah Transit Authority for commuter 
      train operation along the Wasatch Front. A licensing program for use of 
      Union Pacific trademarks is announced.
 
      Union Pacific operates a special train carrying the 
      Olympic flame across 11 states over more than 3,200 miles enroute to the 
      Winter Games in Salt Lake City. 
      2003 – The Union Pacific 
      Museum is opened at the historic Council Bluffs Carnegie Library.