Inside 85 years of Bob Hope, Robin Williams, Loretta Lynn and the stars who answered the USO’s call—just in time for Memorial Day. Photo by Donaldson Collection/Michael Ochs Archives/Getty Images Key Points The USO entertains troops worldwide with celebrity performances, boosting morale since 1941. Stars like Monroe, Hope, and Williams have considered tours among their most gratifying experiences. “We go wherever our service members go,” said USO CEO Lt. Gen. Michael Linnington.