January 20 - The Elizabeth City and Norfolk Railroad, which later became the original Norfolk Southern Railroad, is chartered to build a railroad line between Norfolk, Virginia, and Elizabeth City, North Carolina.
February 24 - Delaware and Hudson Canal Company leases the Albany and Susquehanna Railroad, which extended from Albany to Binghamton, New York.
March 7 - Great Indian Peninsular Railway completes link between Itarsi and Jabalpur where it connects with the East Indian Railway, completing the rail connection from Bombay to Calcutta.
March 24 - Pennsylvania Railroad signs a 999-year lease of the Erie and Pittsburgh Railroad.
March 28 - Construction on the Kansas Pacific Railway reaches Kit Carson, Colorado.
June - The Denver Pacific Railway completes construction of its mainline between Denver, Colorado, and Cheyenne, Wyoming.
July 24 - The first railroad car to travel the entire distance from the Pacific to the Atlantic coast of the United States arrives in New York City.
Construction crews on the Kansas Pacific working eastward from Denver and westward from Kansas City meet at Strasburg, Colorado.
The Atchison, Topeka and Santa Fe Railroad, building westward from Topeka, reaches Emporia, Kansas.
The Texas legislature approves the Missouri-Kansas-Texas Railroad (MKT) charter, which was originally granted by Kansas, allowing the MKT to build into the state.
Official opening of the Tower Subway beneath the River Thames in London. Although this lasts as a railway operation only until November, it demonstrates the technologically successful first use of the cylindrical wrought iron tunnelling shield devised by Peter W. Barlow and James Henry Greathead and of a permanent tunnel lining of cast iron segments.
August 15 - Construction on the Kansas Pacific Railroad, building westward from Kansas, reaches Denver, Colorado.
September 12 [O.S. August 30] 1870 - Russian emperor Alexander II inaugurates through services between Saint Petersburg and Helsinki (Finnish Railways).
September 12 - Completion of the Portland and Ogdensburg Railroad from Portland, Maine to Sebago Lake causes abandonment of the parallel Cumberland and Oxford Canal.
Ginery Twichell succeeds Henry Keyes as president of the Atchison, Topeka and Santa Fe Railway.
The Colorado Central Railroad completes construction of its mainline between Golden, Colorado and Denver, Colorado.
October 24 - First railway in the Governorate of Estonia was opened on the route Paldiski–Reval (Tallinn)–Narva–Gatchina. It was connected with the Saint Petersburg–Warsaw railway on the same year. Baltic Railway Society extended the line in 1870 from Gatchina to Tosno, so it would be connected to nowadays October Railway.
December 12 - The Stairfoot rail accident in England kills 15 people
December 26 - The Hatfield rail crash (1870) in England kills 8.
The Southern Pacific Railroad and Central Pacific Railroad operations are merged under the Southern Pacific name.
Northwestern Pacific Railroad predecessor San Francisco and North Pacific Railroad begins service between San Francisco Bay and Santa Rosa, California.
Joy valve gear for steam locomotives is patented in the United Kingdom.
July 29 - Henry Fowler, Chief Mechanical Engineer of the Midland Railway 1909–1923 and of the London, Midland and Scottish Railway 1925–1931 (d. 1938).
April 26 - Zerah Colburn (locomotive designer) (suicide) (b. 1832).
December - Byron Kilbourn, president of Milwaukee and Mississippi Railroad 1849-1852 (b. 1801).
December 8 - Thomas Brassey, English railway contractor who supervised the construction of more than 6500 miles (10461 km) of track around the world (b. 1805).
George S. Griggs, pioneering master mechanic of American steam locomotives (b. 1805).
1870 in rail transport Wikipedia
This article lists events related to rail transport that occurred in 1870.