Abraham Erskine was the German Jewish American scientist almost solely responsible for the formula which became the "Supersoldier Serum", and thus the project that turned Steve Rogers into Captain America. In the movieverse, the serum vastly magnifies existing traits, thus bringing out all the goodness in Rogers and, conversely and earlier, showing in Johann Shmidt the "Red Skull" and terrifying evil of his true nature.
In "Captain America: The First Avenger", Dr. Erskine is assassinated by an agent of HYDRA as the test on Rogers proves successful, and his work is lost, since he was careful not to leave written records, for fear of the consequences in the wrong hands.
Elements of his work, presumably reverse engineered, are to be found in everything from Dr. Banner's gamma research to the Extremis serum. He is invoked in the "Pilot" when Jemma Simmons points out that the Centipede serum is based on that of Dr. Erskine.