The 19th century lasted from 1801 through 1900 in the Gregorian calendar. Historians sometimes define a "Nineteenth Century" historical era stretching from 1815 (The Congress of Vienna) to 1914 (The outbreak of the First World War); alternatively, Eric Hobsbawm defined the "Long Nineteenth Century" as spanning the years 1789 (the French Revolution) to 1914. Some other scholars even include the preceding period, starting a Very long 19th century at the American Declaration of Independence.