- May 17
- 1853 – The New York Central Railroad is formed through the merger of ten smaller railroads in New York under the direction of Erastus Corning.
- 1906 – The Simplon Tunnel (pictured) between Italy and Switzerland, the world’s longest tunnel until 1979, opens to rail traffic.
- 1908 – Trains operating through the St. Clair Tunnel connecting Sarnia, Ontario, and Port Huron, Michigan, begin using electric locomotives instead of steam locomotives.
- 1939 – King George VI and Queen Elizabeth arrive at Wolfe's Cove, Quebec, to begin a tour of Canada; the tour train is pulled by Canadian Pacific Railway 4-6-4 locomotives 2850 and 2851, earning the class the name Royal Hudson.