Born in Germany, Erskine was forcefully recruited into the German Research Divisions in 1939. When the Nazis assumed control of the German government, Erskine was forced into service under Col. Johann Schmidt. Schmidt was experimenting with alien biological weapons called Terrigen Mists in an effort to produce the Ubermensch, a superior, evolved human being. Schmidt exposed himself to the Terrigen Mists and the result enhanced his intellect and physique, but mangled his face and drove him insane.
Erskine fled to the United States and volunteered as an ally. He was assigned to the Strategic Scientific Reserve and his research repurposed into the Super-Soldier project. Unfortunately, a German assassin shot and killed him on the eve of his success, and Erskine died in the arms of the one and only super-soldier: Steve Rogers.