health effects began to become more prevalent. In Germany, anti-smoking groups, often associated with anti-liquor groups, first published advocacy against the consumption of tobacco in the journal Der Tabakgegner (The Tobacco Opponent) in 1912 and 1932. In 1929, Fritz Lickint of Dresden, Germany, published a paper containing formal statistical evidence of a lung cancer–tobacco link. During the Great Depression, Adolf Hitler condemned his earlier smoking habit as a waste of money, and later with stronger assertions. This movement was further strengthened with Nazi reproductive policy as women who smoked were viewed as unsuitable to be wives and mothers in a German family. The movement in Nazi Germany did reach across enemy lines during the Second World War, as anti-smoking groups quickly lost popular support. By the end of the Second World War, American cigarette manufacturers quickly reentered the German black market. Illegal smuggling of tobacco became prevalent, and leaders of the Nazi anti-smoking campaign were assassinated. As part of the Marshall Plan, the United States shipped free tobacco to Germany; with 24,000 tons in 1948 and 69,000 tons in 1949. Per capita yearly cigarette consumption in post-war Germany steadily rose from 460 in 1950 to 1,523 in 1963. By the end of the 20th century, anti-smoking campaigns in Germany were unable to exceed the effectiveness of the Nazi-era climax in the years 1939–41 and German tobacco health research was described by Robert N. Proctor as "muted". In the UK and the US, an increase in lung cancer rates, formerly "among the rarest forms of disease", was noted by the 1930s, but its cause remained unknown and even the credibility of this increase was sometimes disputed as late as 1950. For example, in Connecticut, reported age-adjusted incidence rates of lung cancer among males increased 220% between 1935–39 and 1950–54. In the UK, the share of lung cancer among all cancer deaths in men increased from 1.5% in 1920 to 19.7% in 1947. Nevertheless, these increases were questioned as potentially caused by increased reporting and improved methods of diagnosis. Although several carcinogens were already known at the time (for example, benzo[a]pyrene was isolated from coal tar and demonstrated to be a potent carcinogen in 1933), none were known to be contained in adequate quantities in tobacco smoke. Richard Doll in 1950 published research in the British Medical Journal showing a close link between smoking and lung cancer. Four years later, in 1954