In the former concentration camps the JLC helped prepare lists of those who perished and those who survived. It also established elaborately cross-referenced card files on people seeking loved ones, which were used in answering the JLC's portion of the avalanche of heart-wrenching correspondence that was passed from the Forward to the Workmen's Circle, to the landsmanshaftn (home-town associations), and to the many Jewish relief organizations.

The JLC also acted as a central clearinghouse, passing along innumerable requests that would spark the sympathy of smaller, more specialized groups. A plea is received from a company of Yiddish actors, starving in a DP camp. Send it to the Hebrew Actors' Union. Two emigre printers have arrived in New York. Call the Hebrew-American Typographical Union. Children's hats are needed. Notify the Millinery Workers. A family in Brooklyn are searching for their nephew, a rabbinical student. Contact Agudas Israel. Making ample use of the columns of the Forward and of Yiddish-language radio station WEVD, the JLC publicized the needs of victims of Nazism and anti-Jewish persecution around the world.

The first postwar national conference of the JLC, held in Atlantic City in 1947, was both a solemn and a heartening event. Haakon Lie of the Norwegian Labor Party, Daniel Mayer of the French Socialists, and many others expressed the deep gratitude of European comrades for the JLC's wartime assistance. Delegates listened to survivors of the camps and to others who had been rescued through JLC efforts. Vladka Meed told of her missions as an underground courier, bringing JLC aid to hidden survivors after the Warsaw uprising:

The money that you sent was the basis for all our later illegal activities. Your help reached the various cities in Poland, the hideouts, the dugouts, forests and camps ... Our only justification for continuing to live is to fulfill our obligations to those who have passed on....