Updated: May 6, 2021
President Truman appointed James McDonald to be "Special Representative of the U.S. to Israel in 1948, and this his title was officially changed to Ambassador.
Well before the State of Israel was formed, McDonald was outspoken for the cause of protecting the Jewish people. Maybe this was because he was the first American to hear Hitler publicly condemn the Jews.
James was originally from the Midwest originally and raised Catholic. He wasn't particularly an advocate for Jewish rights. But after he heard Hitler's speech and hatred for the Jews, that all changed.
He was at one point the Commissioner for Refugees coming from Germany before the Holocaust. However, he resigned because they wouldn't help Jewish refugees, and U.S president, Franklin D. Roosevelt, would not allocate funds to help. When he finally became Ambassador, he was able to help Israel and the Jewish people even more.
When the State Department wanted to put sanctions on Israel, McDonald stopped them so that Israel could keep hold of the Negev. He understood that Israel needs a strong Southern border to defend itself. Especially after the atrocities, he saw in the Holocaust, James McDonald knew Israel needed to be strong. Where others stood and watched, James McDonald spoke up. Both before 1948 and after, he proved himself a true friend of Israel.