Question: Louis Wilson Menk, was an American railway worker and executive, he served as the last president of Northern Pacific Railway 1966-1970, before the railroad was merged into which United States-based railroad company formed from a merger of four major U.S. railroads?

Context articles: Louis W. Menk
Spokane, Portland and Seattle Railway
Burlington Northern Railroad
Samuel Morse Felton, Sr.
Soo Line Railroad
Northern Pacific Depot
V&amp;S Railway
International Railway (New York–Ontario)
John A. Haydon
Missouri Pacific Railroad

Louis Wilson Menk (born April 8, 1918 in Englewood, Colorado, died November 27, 1999) was an American railway worker and executive.
 He served as the last president of Northern Pacific Railway 1966-1970, before the railroad was merged into Burlington Northern Railroad.
 Menk was also selected as "Modern Railroads" (now Railway Age) "Man of the Year" for 1967, an award that has continued annually and is now known as Railroader of the Year.
The Spokane, Portland & Seattle Railway (SP&S) (reporting mark SPS) was a United States-based railroad incorporated in 1905.
 It was a joint venture by the Great Northern Railway and the Northern Pacific Railway to build a railroad along the north bank of the Columbia River.
 Remnants of the line are currently operated by BNSF Railway.
The Burlington Northern Railroad (reporting mark BN) was a United States-based railroad company formed from a merger of four major U.S. railroads.
 Burlington Northern operated between 1970 and 1996.
Samuel Morse Felton, Sr. (1809–1889) was a civil engineer and railroad executive.
 He was the Superintendent and engineer of the Fitchburg Railroad 1843-1851 and president of the Philadelphia, Wilmington and Baltimore Railroad from 1851-1865.
 Felton left the PWBRR to become President of the Pennsylvania Steel Company.
 While at Pennsylvania Steel, Felton also served as a director of several railroads, including the Philadelphia, Wilmington and Baltimore Railroad, the Lehigh Coal & Navigation Company, the Northern Pacific Railway, and the Ogdensburg and Lake Champlain Railroad.
 In 1869 he was appointed by President Ulysses S. Grant as a Commissioner to inspect Pacific Railroads.
The Soo Line Railroad (reporting mark SOO) is the primary United States railroad subsidiary of the Canadian Pacific Railway (CP), controlled through the Soo Line Corporation, and one of seven U.S. Class I railroads. Although it is named for the Minneapolis, St. Paul and Sault Ste. Marie Railroad (MStP&SSM), which was commonly known as the Soo Line after the phonetic spelling of Sault, it was formed in 1961 by the consolidation of that company with two other CP subsidiaries, the Duluth, South Shore and Atlantic Railroad and Wisconsin Central Railroad.
 It is also the successor to other Class I railroads, including the Minneapolis, Northfield and Southern Railway (acquired 1982) and Chicago, Milwaukee, St. Paul and Pacific Railroad (Milwaukee Road, acquired at bankruptcy in 1985).
 On the other hand, a large amount of mileage was spun off in 1987 to Wisconsin Central Ltd., now part of the Canadian National Railway.
 The Soo Line and the Delaware and Hudson Railway, the CP's other major subsidiary (before the 2008 DM&E acquisition), presently do business as the Canadian Pacific Railway, and most equipment has been repainted into the CP's scheme, but the U.S. Surface Transportation Board groups all CP's U.S. subsidiaries under the Soo Line name for reporting purposes.
Northern Pacific Depot, or Northern Pacific Railway Depot, or Northern Pacific Passenger Depot, or Northern Pacific Railroad Depot, or Northern Pacific Railway Passenger Depot may refer to the following stations in the United States:
The V&S Railway (reporting mark VSR) is a shortline railroad that operates two disconnected lines in the U.S. state of Kansas.
 It is affiliated with A&K Railroad Materials, a scrap dealer whose primary business is buying marginal rail lines with the intent of abandoning them and selling the material as scrap for immediate cash.
 The company acquired its first line, a former Atchison, Topeka and Santa Fe Railway line between Medicine Lodge and a BNSF Railway junction at Attica, from the Central Kansas Railway in 2000.
 In 2006 it expanded its operations by acquiring from the Hutchinson and Northern Railway (reporting mark HN) a short segment of former interurban in eastern Hutchinson, where it interchanges with the BNSF Railway, Union Pacific Railroad, and Kansas and Oklahoma Railroad.
 The V&S also operates a line in Colorado as the Towner Railway, which began serving a former Missouri Pacific Railroad line that had most recently been the Colorado, Kansas and Pacific Railway in 2005.
 Other railroads under common control with the V&S are the out-of-service Kern Valley Railroad in Colorado, the Gloster Southern Railroad in Louisiana and Mississippi, the Grenada Railway and Natchez Railway in Mississippi, a portion of the former Rock Island from St. Louis to Union, Missouri operated by the Missouri Central and the Southern Manitoba Railway in Manitoba.
The International Railway Company (IRC) was a transportation company formed in a 1902 merger between several Buffalo-area interurban and street railways.
 The city railways that merged were the "West Side Street Railway", the "Crosstown Street Railway" and the "Buffalo Traction Company".
 The suburban railroads that merged included the "Buffalo & Niagara Electric Street Railway", and its subsidiary the "Buffalo, Lockport & Olcott Beach Railway"; the "Buffalo, Depew & Lancaster Railway"; and the "Niagara Falls Park & River Railway".
 Later the IRC acquired the Niagara Gorge Railroad (NGRR) as a subsidiary, which was sold in 1924 to the Niagara Falls Power Company.
 The NGRR also leased the "Lewiston & Youngstown Frontier Railroad".
John A. Haydon (1830 – 1902) was a prominent American surveyor and civil engineer.
 As a self-taught civil engineer, Haydon made significant contributions to American railroading.
 Haydon's railroad career spanned the Baltimore and Ohio railroad expansion to the Ohio river in 1853 and several other railroads to the last transcontinental railroad, the Northern Pacific railway.
 Haydon led the 1872 Yellowstone River expedition, where he faced a Sioux Indian skirmish led by Sitting Bull, Red Cloud and Crazy Horse at the Battle of Pryor's Creek, Montana.
 He also served as a captain in the Confederate army Corps of Engineers under Generals Tilghman and Beauregard; captured at the battle of Fort Henry, early in the Civil War in 1862, he was paroled at Aiken, South Carolina, in November 1862 to serve the rest of the war, including the Richmond–Petersburg Campaign.
 In the latter part of his life, he worked locating branch railroads for the Western Maryland railroad.
The Missouri Pacific Railroad (reporting mark MP) , commonly abbreviated MoPac, with nickname of The Mop, was one of the first railroads in the United States west of the Mississippi River.
 MoPac was a Class I railroad growing from dozens of predecessors and mergers, including the St. Louis, Iron Mountain and Southern Railway (SLIMS), Texas and Pacific Railway (TP), Chicago and Eastern Illinois Railroad (C&EI), St. Louis, Brownsville and Mexico Railway (SLBM), Kansas, Oklahoma and Gulf Railway (KO&G), Midland Valley Railroad (MV), San Antonio, Uvalde and Gulf Railroad (SAU&G), Gulf Coast Lines (GC), International-Great Northern Railroad (IGN), New Orleans, Texas and Mexico Railway (NOTM), Missouri-Illinois Railroad (MI), as well as the small Central Branch Railway (an early predecessor of MP in Kansas and south central Nebraska), and joint ventures such as the Alton and Southern Railroad (AS).