Calling Lincoln "fascist" is just as ludicrous as calling, say, George Washington a "fascist".
Both loved their country, neither was a "fascist".
First of all, the political word "fascism" wasn't even invented until the First World War and Mussolini's party in Italy, so nobody before that could necessarily match Mussolini's definition.
Second, fascists all claimed to be socialists -- i.e., National Socialists -- which in no way describes George Washington or Lincoln.
Third, like Washington's, Lincoln's actions merely defeated a military power that not only provoked and started war against the United States, but in the Confederacy's case, formally declared war on the United States.
So there's nothing "fascist" about defeating a declared enemy of the United States.
Oddly, fascism is at its essence “Let us hang together or we shall assuredly hand separately.” which sounds a bit like Ben Franklin to me.
Mussolini used the symbol because it harked back to the Romans. He wanted to ignore the intervening conquest of Italy by Goths, Byzantine Greeks, Crusaders, French, Austro-Hungarians and Arabs (in no particular order).