Information came from the following: "Wall Street and the Rise of Hitler", by Professor Antony C. Sutton, and Joseph Borkin's book; "The Crime and Punishment of IG Farben"
Quite a bit of the financing for Hitler and the Nazis came from affiliates or subsidiaries of many U.S. citizens and firms, Henry Ford’s help began in the twenties, and were simply included in with payments from American I.G. (Farben) and General Electric which started as early as 1933. The Standard Oil (New Jersey), American I.G. (Farben) and I.T.T. subsidiary payments through Heinrich Himmler continued up to 1944. Walter Teagle, a close Roosevelt associate and backer, as well as an NRA administrator; along with banker Paul Warburg (his brother Max Warburg was on the board of I.G. Farben in Germany), and Edsel Ford were the directors of the American I.G. (Farben) board.
J.P. Morgan Bank, Guaranty Trust, Chase Manhattan Bank, at least three Wall Street houses (Dillon, Read; Harris, Forbes; and, National City Company for sure), Standard Oil (New Jersey), Du Pont, Dow Chemical, General Motors, Ford Motors, and General Electric (A.E.G.) of the United States helped or profited in some manner. G.E. (A.E.G) rounded out its support by technical cooperation with Krupp, which seems to have been aimed at restricting the U.S. development of tungsten carbide. I.T.T. held a 28 percent interest in Focke-Wolfe aircraft, American Ford owned French Ford and Ford Werke of Belgium and profited from supplying the German Wehrmacht with cars and trucks through out the war. Standard Oil's most egregious role (beyond profiteering), was with technical aid to Nazi development of synthetic rubber and synthetic gasoline through a U.S. research company under the management and control of Standard Oil.
Then the Ethyl Gasoline Company, jointly owned by Standard Oil and General Motors, was instrumental in supplying vital tetra-ethyl lead assistance to Nazi Germany with the clear knowledge that the tetra-ethyl lead was for Nazi military purposes. I also believe that the dividends to both GM (from Opel) and Ford from their European subsidiaries continued all through the war years too, through the Swiss and the Swedes. That may have been justified as "weakening" the Germany economy and strengthening our own at the same time however. Everybody it seems took advantage of the situation and had fingers in the pie.
The most embarrassing, it would seem to me, is Henry Ford Sr. sending Adolf Hitler a personal monetary "birthday gift" every April 20th through 1944. 1938 was the year he was awarded that medal by Der Fuehrer, and Henry sent something like 10,000, or 20,000 Reichmarks to Hitler through Swiss or Swedish banks every year. Even during the war years, he managed to continue the practice. There was a running joke in Detroit that Hitler had ordered thousands of tanks from Ford’s plant, but didn’t make painting or delivery arrangements. He said he would call ahead on the paint scheme, and pick them up on his way through town.
The U.S. Ambassador in Germany, William Dodd, wrote FDR from Berlin on October 19, 1936 (three years after Hitler came to power), concerning American industrialists and their aid to the Nazis: "Much as I believe in peace as our best policy, I cannot avoid the fears which Wilson emphasized more than once in conversations with me, August 15, 1915 and later: the breakdown of democracy in all Europe will be a disaster to the people. But what can you do? At the present moment more than a hundred American corporations have subsidiaries here or cooperative understandings. The DuPonts have three allies in Germany that are aiding in the armament business. Their chief ally is the I. G. Farben Company, a part of the Government which gives 200,000 marks a year to one propaganda organization operating on American opinion. Standard Oil Company (New Jersey sub-company) sent $2,000,000 here in December 1933 and has made $500,000 a year helping Germans make Ersatz gas for war purposes; but Standard Oil cannot take any of its earnings out of the country except in goods. They do little of this, report their earnings at home, but do not explain the facts. The International Harvester Company president told me their business here, in Germany rose 33% a year (arms manufacture, I believe), but they could take nothing out. Even our airplanes people have secret arrangement with Krupps. General Motor Company and Ford do enormous businesses [sic] here through their subsidiaries and take no profits out. I mention these facts because they complicate things and add to war dangers. (Edgar B. Nixon, ed., Franklin D. Roosevelt and Foreign Affairs, Volume III: September 1935-January 1937, [Cambridge: Belknap Press, 1969], p. 456.)