He helped establish the nationwide United Jewish Appeal in 1939 and made other charitable grants through the William Rosenwald Family Fund.

In January 1939, Rosenwald's National Coordinating Committee Fund joined with Rabbi Jonah Wise of the American Jewish Joint Distribution Committee, Rabbi Abba Hillel Silver of the United Palestine Appeal, to form the United Jewish Appeal for Refugees and Overseas Needs.

[5] The founders emphasized that the funds needed to support Jews in Europe and Palestine would be triple to quadruple the amount raised in the previous year.

While the organizations would raise funds together, the Joint Distribution Committee would assist Jews in Europe, the United Palestine Appeal would aid the Jewish community in Palestine, including refugees from Europe arriving there and the National Coordinating Committee Fund would assist refugees arriving in the United States.

In 1960, Rosenwald received the Solomon Bublick Award of the Hebrew University of Jerusalem in recognition of his "significant contribution to the progress and development of Israel”.