Which factor was an important contribution to the start of the world war 1

The assassination of Archduke Franz Ferdinand of Austria-Hungary.

Explanation:

The start of of the first world war was the assassination of Austrian archduke, Franz Ferdinand and his wife, on 28th June 1914 by Bosnian revolutionary, Gavrilo Princip. Princip was part of an assassin group with 5 other people led by Danilo Ilića, Bosnian Serb and a member of the Black Hand secret society. The political objective of the assassination was to break off Austria-Hungary's South Slav provinces so they could be combined into a Yugoslavia.

abraham lincoln, according to anyone who was connected with agriculture, represented the worst of northern politicians. shortly after lincoln was elected, south carolina seceded from the union. they along with other southern states, retained their anger. in a way, it was their own fault: the democrats were split in the south. some wanted slavery to be extended in other states that were about to join the union and some didn't want it badly enough. lincoln had a solid backing from his party: the republicans were united in not wanting slavery to be expanded.