When he returned to Paris after World War II, he learned that three of his 13 siblings had not been taken away and had survived the Nazi occupation of France. Clary returned to the entertainment business and began singing songs that not only became popular in France, but in the United States as well. Clary made his first recordings in 1948; they were brought to the United States on wire and were issued on disk by Capitol Records. He went to the U.S. in October 1949. One of Clary's first American appearances was a French language comedy skit on "The Ed Wynn Show" in 1950. Clary later met Merv Griffin and Eddie Cantor. This eventually led to Clary meeting Cantor's daughter, Natalie Cantor Metzger, whom he married in 1965, after being "the closest of friends" for 15 years. Cantor later got Clary a spot on "The Colgate Comedy Hour". In the mid-1950s, he appeared on NBC's early sitcom "The Martha Raye Show" and on CBS's drama anthology series "Appointment with Adventure". Clary's comedic skills were quickly recognized by Broadway, where he appeared in several popular musicals, including "New Faces of 1952", which was produced as a film in 1954. In 1952, he appeared in the film "Thief of Damascus" which also starred Paul Henreid and Lon Chaney, Jr. In 1958, he guest-starred on NBC's "The Gisele MacKenzie Show". He also guest starred on the colour revival of ‘’The Munsters’’ – ‘‘The Munsters Today’’ in 1989 as Louis Schecter, Lily's acting coach, in the episode "Green Eyed Munster". In 1965, the diminutive 155 cm (5 ft 1 in) Clary was offered the role of Corporal Louis LeBeau on a new television sitcom called "Hogan's Heroes", and he accepted the role when the pilot sold. The series was set in a German prisoner of war (POW) camp during World War II, and Clary played a French POW who was a member of an Allied sabotage unit operating from inside the camp. Asked about parallels between LeBeau's incarceration and his own, Clary said, "Stalag 13 is not a concentration camp. It's a POW camp, and that's a world of difference. You never heard of a prisoner of war being gassed or hanged. When the show went on the air, people asked me if I had any qualms about doing a comedy series dealing with Nazis and concentration camps.