'I find that so long as you render service - no matter where and how - all men speak the same tongue, and hearts beat the same." So said Henry Morgenthau Sr. in 1916, his third year as US ambassador to the Ottoman Empire. In a brief time as President Woodrow Wilson's envoy, he had indeed rendered service, providing succor and sounding alarms that firmly established his place in Jewish history and made him a hero to Armenians. Deeply affected by the dire poverty of the Jews in Palestine, Morgenthau in 1914 cabled his friend Jacob Schiff in New York: "Palestinian Jews facing terrible crisis belligerent countries stopping their assistance serious destruction threatens thriving colonies fifty thousand dollars needed." It was no small amount in those days, but Schiff quickly raised the funds for a relief project that evolved into the Joint Distribution Committee. The next year, fearful of the fate of Armenians in the Ottoman Empire, he cabled Washington, reporting that "from harrowing reports of eye witnesses it appears that a campaign of race extermination is in progress." To this day, Henry Morgenthau Sr. is revered by Armenians for alerting the world to the Armenian genocide. These cables are among the documents, memorabilia, photographs and films in a new exhibit "The Morgenthaus: A Legacy of Service" at the Museum of Jewish Heritage in New York. The exhibit, which opened this month in lower Manhattan and runs through 2010, covers the public and communal service of three generations of Morgenthaus: Henry Sr., Henry Jr. and Robert. Henry Jr. was president Franklin D. Roosevelt's Treasury secretary during the Depression, and helped prepare the economy for World War II. He still held that post in January 1944 - the Jew on the president's cabinet at the most frightening moment in modern Jewish history - when his office took a remarkable step. It challenged the US State Department for failing to rescue European Jews. His staff wrote a report "on the acquiescence of this government in the murder of Jews." Morgenthau edited the title, calling it a "personal report to the president," but he did not mince words with Roosevelt, whom he had first met as a neighbor in upstate New York. "One of the greatest crimes in history, the slaughter of the Jewish people in Europe, is continuing unabated," he wrote. He assailed the "utter failure of certain officials in our State Department â€¦ to take any effective action to prevent the extermination of the Jews in German-controlled Europe." Only days after receiving the report, Roosevelt signed Executive Order 9417, creating the War Refugee Board. Many argue that the board, which saved some 200,000 European Jews, did too little too late. But Roosevelt's tarnished record during the Holocaust and that of his administration only enhance, rather than diminish, the significance of the actions taken by Morgenthau, who later was an energetic fund-raiser for Jewish and Israeli causes. (The moshav Tal Shahar was founded in 1948 and named after him; "Morgenthau" translates from the German to "morning dew.") "What I want is intelligence and courage - courage first and intelligence second," Henry Jr. once said. He had them. His son Robert has been the Manhattan district attorney for more than a generation. (The fictional Adam Schiff, the original district attorney on the television program Law & Order, was reportedly modeled on Morgenthau.) His office has been famous not only for its cases, but for the attorneys and judges who cut their lawyerly teeth there. Most recently, that attention focused on the newest Supreme Court justice, Sonia Sotomayor, who joined Morgenthau's staff in 1979, when she was 25. A handwritten note from Sotomayor is on exhibit: "Bob - Few can say they have a friend and mentor like you. I was blessed the day we met. Thank you for all your support. Sonia" Now 90, the district attorney is retiring after some 35 years as the city's prosecutor. With his retirement, this "Morgenthau century" of prominent public service [by the family] will end. HENRY SR. WAS born in 1856 in Mannheim, Germany; his family came to New York a decade later. He had a career in law and real estate before he was tapped by Wilson. "I had to wait until I was 55 to earn enough money to afford to go into public service," Henry Sr. told his grandson. "You don't have that excuse." Robert got the message. In addition to his very public role as district attorney, Robert has been actively involved in charitable and civic institutions, such as the Police Athletic League, whose activities include day care, summer camp, employment and sports programs for New York City's children and youth. He also is chairman of the Museum of Jewish Heritage, whose exhibitions are notable, in part, for the wide-ranging and thought-provoking public and educational programming that accompanies them. Morgenthau's relationship to the museum seems coincidental to the exhibit; the family's century of public service merits it. And despite an exhibit that features its chairman's family, the museum does not blindly glorify or whitewash the Morgenthaus' history. For instance, in its summary of Henry Sr.'s 1919 official "commission to Poland" to investigate reports of atrocities against Jews, the exhibit acknowledges that Morgenthau "minimized blame" due the Polish government for the mistreatment of Jews, for which he was strongly criticized. Yet he was profoundly moved by what he witnessed in Poland. "This was the first time I ever completely realized what the collective grief of a persecuted people was like," he said. "The Morgenthaus: A Legacy of Service" is intended not only as a look back at one family's three generations of public service, but to promote it as well. The exhibit (which has material online at www.mjhnyc.org/morgenthaus) urges people to become involved with such causes such as food banks, genocide intervention and Jewish service corps. As he walked through the exhibition with reporters earlier this month, pausing at artifacts and photos, Robert Morgenthau said: "I hope it will encourage people to be involved with public service."