Why did america stay neutral during world war 1?

Isolationism was a major influence, it kept America separate from the war and my means greater than mere distance, it was a strong ideology. President Wilson was a great advocate of it. Even today there are many people who consider this to be a form of selfish cowardice because there was strong feeling in the US that it should help.Many Europeans consider Isolationism to be selfish, even cowardly. It should be noted that America was never officially in WW1  America could easliy afford to go to war from an economic standpoint, but it wrestled with the possible cost in lives as well, for a war that many felt was not the concern of the US. Culturally and socially there was a lot of sympathy for Britain in some quarters, and antipathy in others, depending on your position in society.