Judo in the United States however, the lecture had little effect on mainstream judo growth. The first American to actually study judo was Prof. Ladd from Yale University, in 1889. He trained at the Kodokan in Japan for about ten years; by 1908 about 13 Americans were training there. In 1919, Prof. John Dewey of Columbia University came to visit Prof. Ladd and Master Kano, many years later he took his knowledge back to Columbia and began the first U.S. college judo program. While some students were training in Japan there was some action in the U.S. Perhaps one of the most important figures in
Dan (rank) always use the term Duanwei. Korean martial arts lacked a grading system up until the Japanese occupation (1910–1945) during which a variety of Japanese martial arts were introduced into the Korean school system, most notably judo, karate-do and kendo. After the occupation ended, newly emerging martial arts like taekwondo, tang soo do, soo bahk do and hapkido adopted the dan (단, 段) and "geup" (급, 級) ranks. The dan rank system is also used by "baduk" players. Nowadays, the Korea Taekkyon Association also issues dan ranks to "taekkyeon" practitioners. Someone who has received a dan rank is called a "yudanja"