Because anti-Semitism had been on the rise, Einstein accepted the invitation by Dr. Chaim Weizmann, the president of the World Zionist Organization, for a trip to the United States to raise money.Essentially all of those names who had contributed to the recent development of the quantum theory were at this Solvay Conference, including Bohr, Born, de Broglie, Dirac, Heisenberg, Pauli, and Schrödinger.Heisenberg commented:[9] "Through the possibility of exchange between the representatives of different lines of research, this conference has contributed extraordinarily to the clarification of the physical foundations of the quantum theory.The following list of participants is extracted from the proceedings of the Solvay Conferences in Physics stored in the Solvay archives [11] 1948: (scientific committee – present) Sir Lawrence Bragg, Niels Bohr, Théophile de Donder, Sir Owen Willans Richardson, Jules-Émile Verschaffelt, Hendrik Kramers (scientific committee – absent) Peter Debye, Abram Fedorovich Ioffé, Albert Einstein, Frédéric Joliot-Curie (speakers) C. F. Powell, P. Auger, Felix Bloch, Patrick Blackett, Homi J. Bhabha, Marie-Antoinette Tonnelat on behalf of Louis de Broglie, Rudolf Peierls, Walter Heitler, Edward Teller, R. Serber, Léon Rosenfeld (additional participants) H. Casimir, J. Cockroft, P. Dee, Paul Dirac, Ferretti, O. Frisch, Oskar Klein, Leprince-Ringuet, Lise Meitner, Christian Møller, Francis Perrin, J. Robert Oppenheimer, Wolfgang Pauli, P. Scherrer, Erwin Schrödinger (auditeurs) J. Timmermans, G. Balasse, J. Errera, O. Goche, P. Kipfer, L. Flamache, M. Occhialini, Marc de Hemptinne (secrétaires) E. Stahel, J. Géhéniau, Miss Dilworth, Ilya Prigogine, L. Groven, Léon Van Hove, Yves Goldschmidt, MM Van Styvendael, Demeur, Van Isacker (administrative commission) Jules Bordet, Ernest-John Solvay, Dr F. Héger-Gilbert, E. Henriot, F. van den Dungen.A. Michelson (1907) - E. Rutherford (1908) - J. D. van der Waals (1910) W. Wien (1911) - V. Grignard (1912) - H. Kamerlingh Onnes (1913) - M. von Laue (1914) - W. H. Bragg (1915), W. L. Bragg (1915) - C. G. Barkla (1917) - M. Planck (1918) - J. Stark (1919) - W. Nernst (1920) A. Einstein (1921), F. Soddy (1921) - N. Bohr (1922), F. W. Aston (1922) - K. M. Siegbahn (1924) - J. Franck (1925), G. Hertz (1925) - J. Perrin (1926) - A. H. Compton (1927), C. T. R. Wilson (1927), H. Wieland (1927) - O. Richardson (1928) - L. de Broglie (1929) W. Heisenberg (1932), I. Langmuir (1932) - P. A. M. Dirac (1933), E. Schrödinger (1933) - J. Chadwick (1935), F. Joliot-Curie (1935), I. Curie (1935) - W. Debije (1936) - E. Fermi (1938), R. Kuhn (1938) - E. Lawrence (1939), L. Ruzicka (1940) G. de Hevesy (1943) - W. Pauli (1945) - P. Bridgman (1946) - P. Blackett (1948) J. D. Cockcroft (1951), E. T. Walton (1951) - M. Born (1954), W. Bothe (1954).