When did World War 1 start and end?

Answer 1

1914-1918

Answer 2

World War I as a declared state of war lasted from July 28, 1914 to November 11, 1918.

After a decade of unstable alliances and military buildups, World War I was triggered in 1914 by the assassination of Archduke Ferdinand. It ended in 1919 with the Treaty of Versailles.

(See related question below.)
World War 1 started in July 28 1914 and ended November 11 1918

July 1914

It ended November 11, 1918
The war began with the declaration of war by Austria-Hungary against Serbia on July 28, 1914, and within a week it had spread to involve most of Europe. The war ended with the Armistice on November 11, 1918. This was only an agreement to cease fighting, not a surrender. The formal peace treaties officially ending the war did not come until later, with the Versailles Treaty bringing an official end to the war with Germany on June 28, 1919, but there were other treaties. The final Treaty was the Treaty of Lausanne, which brought to an official end the war between the Allied Powers and Turkey, August 23, 1923.
The beginning of World War 1 is generally considered to have started with the spark of the assassination of the Archduke Franz Ferdinand of Austria on June 28, 1914. The first official war declaration/invasion was on July 28, 1914. The war ended on 11-11-1918 (Armistice Day).
World war one started in 1914 and ended in 1919 but some people say that it ended in 1918 but that is when the fighting and battle stopped.

Answer 3

1664 to 1991