"It is a German illusion to believe in the possibility of creating an intellectual capital as long as the so-called educated people are almost proud of their inadequate understanding of urban planning." In 1931 he held a lecture tour through South America, particularly in Argentina, where he attended a local convention on urban planning at Mar del Plata. Hegemann gave a lecture criticising the European aesthetics patterns and planning of this resort city. Back to Germany, he devoted himself increasingly to warnings against the National Socialists in a series of political articles, culminating in the book "Entlarvte Geschichte" ("History Unmasked"). Hegemann fled Germany in February, 1933 (the month after Hitler took power), upon publication of his book, "Entlarvte Geschichte," dedicated sarcastically to Adolf Hitler. In May, 1933 he was denounced by the Nazis as an "Historical Forger," and his books were burned in the Nazi book burnings. After several months in Geneva and France, Hegemann was invited by Alvin Johnson to teach urban planning at The New School for Social Research in New York beginning in November 1933. That October Hegemann left Europe for the United States with his wife and four young children. He was one of many intellectuals essentially exiled by Nazi Germany in the 1930s. Upon arriving in New York City on November 4, 1933 Hegemann opined that the German people would not tolerate Hitler for more than two more years. He began lecturing at the New School and organizing assistance for intellectuals and scholars detained by the Nazis in Germany. In 1935 he was also retained as a lecturer at Columbia University. The Nazis seized Hegemann's house in Nikolassee in 1935, and in 1938 revoked his doctorate. Meanwhile, he made efforts to stir public opinion in the case of Carl von Ossietzky, another German critic of Hitler, who was arrested and imprisoned by the Nazi's in the same month that Hegemann left Germany. He also wrote in support of Roosevelt's New Deal. Hegemann saw the rise of Hitler in Germany as emerging from a historical context of Germans celebrating and idealizing strong men. Characteristically overstating the point, he criticized a century or more of "craving for submission" by German professors, bureaucrats and professionals, and observed that if Hitler ever decided to stop enslaving the nation, he would be "overwhelmed by an irresistible rush into ever deeper submission" by those with "collusive attitudes toward war-hungry German nationalism."