Pollack jokes (refering to Polish people as "Pollacks") came about amidst the start of World War II. When Germany invaded Poland in 1939, Americans were not very aware of global politics or conflicts, and President Roosevelt had instituted the Neutrality Acts keeping the U.S. out of the conflict for the time being. When word spread in America of the very quick defeat of Poland by German and Russian forces (just over a month), Pollack jokes came about making fun of the Polish people.