 Handwerker was born in Galicia, a former kingdom and constituent part of the Austro-Hungarian Empire in the partitioned Poland under the Austrian rule that roughly spanned the contemporary Poland-Ukraine border.One of 13 children of a poor Jewish shoemaker, he immigrated to the United States in 1912.Handwerker found work as a delivery boy and later obtained a job slicing bread rolls at Feltman's German Gardens, a restaurant in Coney Island, Brooklyn.