The Saint Petersburg–Moscow railway opens
The bend 'from Nicholas I's finger' was built 26 years later

The line opened on 1 November 1851, and its straightness spawned a legend: Nicholas I drew it with a ruler, his pencil skirted his finger, and builders dutifully added a bend. In fact the Verebye bypass was built only in 1877 to avoid a steep 17-km gradient.
Wikipedia (Russian) · Wikipedia (English) · 19th century
Meanwhile around the world (±25 years)
Europe
- 1845–1852 Great Famine in Ireland — 6 years earlier
- 1848–1849 Revolutions of 1848 — 3 years earlier
- 1848 The Communist Manifesto — 3 years earlier
- 1859 Darwin's On the Origin of Species — 8 years later
- 1861 Unification of Italy — 10 years later
Middle East
- 1828 Treaty of Turkmenchay — 23 years earlier
- 1839 The Edict of Gülhane opens the Tanzimat — 12 years earlier
- 1839–1842 First Anglo-Afghan War — 12 years earlier
- 1876–1878 The first Ottoman constitution — 25 years later
Africa
- c. 1835–1846 The Great Trek — 16 years earlier
- 1847 Liberia declares independence — 4 years earlier
- 1869 Opening of the Suez Canal — 18 years later
Asia
- c. 1831 Hokusai's Great Wave off Kanagawa — 20 years earlier
- 1839–1842 First Opium War — 12 years earlier
- 1850–1864 Taiping Rebellion — 1 year earlier
- 1853–1854 Commodore Perry's Black Ships — 2 years later
- 1868 Meiji Restoration — 17 years later
Americas
- 1846 First public demonstration of ether anaesthesia — 5 years earlier
- 1846–1848 Mexican–American War — 5 years earlier
- 1861–1865 American Civil War — 10 years later
- 1863 Emancipation Proclamation — 12 years later
- 1876 Invention of the telephone — 25 years later
Oceania
- 1851 The Australian gold rushes — same year
Alive at the time
- Charles Darwin (aged 42)
- Abraham Lincoln (aged 42)
- Karl Marx (aged 33)
- Queen Victoria (aged 32)
- Fyodor Dostoevsky (aged 30)
- Leo Tolstoy (aged 23)
- Dmitri Mendeleev (aged 17)
- Pyotr Ilyich Tchaikovsky (aged 11)
- Thomas Edison (aged 4)
- Nicholas I (aged 55)