Klein was one of several design leaders raised in the Jewish community in the Bronx, along with Robert Denning and Ralph Lauren. He became a of Baron de Gunzburg, through whose introductions he became the toast of the New York elite fashion scene even before he had his first mainstream success with the launch of his first jeans line. He was immediately recognized for his talent after his first major showing at New York Fashion Week. He was hailed as the new Yves Saint Laurent, and was noted for his clean lines.