On October 16, 1940, he joined the United States Army and was assigned to the 106th Field Artillery Regiment at Fort McClellan, Anniston, Alabama.
He was later stationed in Buckinghamshire, England and designed scale models of the beaches in preparation for the Normandy landings.
He worked with the "Monuments Men" to assess damage of cultural sites in Darmstadt, Germany.
Using his "pretzel-bending" technique, Dlugosz rolled clay into strips and bent them together for a lattice-work effect, resulting in sculpture with an open rather than a solid interior His work was exhibited at the Metropolitan Museum of Art in New York City, the École nationale supérieure des beaux-arts and the Louvre in Paris.
In 1982, his bust of Lech Wałęsa—surrounded by bars because the Polish labor leader was jailed by the Communist regime—was blessed by Pope John Paul II in the Vatican.