Dan (rank) is by far the most recognizable symbol to the general public. The highest dan ranks are sometimes reserved for the founder or leaders of a style and only high-ranking students can be promoted to them. For example, only five living people hold a tenth dan in judo and only about thirty-five worldwide have been promoted to the rank since its inception; of those 10th dan promotions only fifteen were conferred by the Kodokan, all of them to Japanese judoka. This has led to upper level ranks becoming extinct in some arts. In other styles, the dan ranks are not the
Judo in the United States AAU sport, and there have been national competitions and tournaments ever since. The United States formed an Olympic team and competed in the 1964 Summer Olympics, which it continues to do to this day. Judo is now practiced by and estimated 100,000 American men, women, and children (25,000 registered in either the USJA, USJF, and USA Judo). America's first major contact exposure to judo came through President Ulysses S. Grant in 1879. He was in Japan for a state visit and observed a judo demonstration. In 1889, Kanō Jigorō gave a lecture on the philosophy of judo to several Americans;