1945: Moo Duk Kwan. The "Moo-duk-kwan" (military virtue training hall) was founded on November 9, 1945, by Hwang Kee (aka. Ki-Chang Hang). Moo Duk Kwan's customs were the strongest among the first five big Kwans. There are two distinct schools of Moo Duk Kwan which evolved from a single source in modern Korean: Tang-soo-do (way of the chinese hand or knife hand) (the Japanese character used to depict this term is the same one used in karate) and Moo-duk-kwan, a division of Taekwondo.

Kee was an expatriate of Korea during much of its Japanese occupation. He said he initially studied the Korean arts of Soo-bak-do and Taekkyon in his homeland before leaving Korea in 1936 to immigrate to China and work for the Southern Manchuria Railroad.

In early interviews, Kee states that he studied numerous systems of Chinese martial arts while living in China. He said that, "At that time, in China, the instruction was not publicized like it is now. Most instructors introduced techniques to only a few people. Only people who would not misuse the knowledge they were allowed to study." Later he said that he also studied a system of karate while in China, though none of this has ever been substantiated. This has lead to debate as to where he actually came upon his advanced knowledge of the martial arts. Nevertheless, he helped modern Korean martial arts gain worldwide acceptance.

Kee formalized his system of self defense on his birthday, November 9, 1945 when he started teaching Moo-duk-kwan as the "Transportation by Rail Committee Tang Soo Do Bu" at the railroad system at Yong San Station, Seoul as a traffic service. Since Kee claimed that he learned kuk-sool when he worked for the Southern Manchuria Railroad in 1935 and since Kee's first students were railway employees, Moo-duk-kwan was called the "Railroad Dojang". The Moo Duk Kwan used the trains to open a school in different railroad stations' storage rooms and spread its power. When someone said Moo Duk Kwan, one would think about the railroad. The school flourished for many years. Then, due to the Korean War, the school was closed on June 25, 1950. When it reopened, Kee changed the name to Moo-duk-kwan.

In 1955, the Moo Duk Kwan Central Gymnasium was opened near Seoul Station in Joong Gu's Dong Ja Dong, Seoul. In the same year, 9 more annex schools were opened and it held the friendly China-Korea International Tangsoodo Championships.

Hwang claimed Gogen Yamaguchi, the founder of Japanese Goju-ryu, as a personal friend. In 1939, Yamaguchi, nicknamed "the cat," was in Manchuria as a Japanese intelligence officer stationed near the Russian border and Hwang's travels took him near the border. From an examination of his later writings, Hwang certainly seems to have been much more influenced by Japanese Karate-do than by Chinese Kuo-shu. The basic pumsae (forms) of Tang-soo-do are nearly identical to the kata (forms) of Shotokan karate. They include the three kijo pumsae (based on the three taikyokyu kata), the five pyong-ann pumsae (based upon the five heian kata), and "basahee" (bassai). On the other hand, the advanced pumsae are named after Chinese styles, including T'aigukkwon ("great absolute fist", or Taijiquan) and Jangkwon ("long fist").

In 1953, Tang-soo-do Moo-duk-kwan began to evolve. It changed its official title to the Korea Soo Bahk Do Association. By 1955 this organization had ten gymnasiums with its central headquarters near Seoul Station in the Jong Gu section of Dong Ja Dong. During this same year, the Moo Duk Kwan Central Gymnasium was opened near Seoul Station in Seoul and the it held the China-Korea International Tang Soo Do Championships. 

At a tournament that Hwang sponsored on Sept. 18, 1958, between the teams of the national railway in honor of the sixtieth anniversary of the railway, the Seoul Railway team took first place, which helped popularize Tang-soo-do.

In 1960, the Korea Tang Soo Do Association changed its name to a Korean traditional name, Korea Soo Bahk Do Association. Kee refused to unify with the KTA , wishing to maintain control over his organization. In March 1965, two advanced students of Kee: Im, Young Tek and Hong, Chong Soo broke away from their master, formed their own branch of Moo-duk-kwan, and merged with the Korea Tang Soo Do Association. Many advanced instructors of the art followed their lead, which accounts for the reason that there are two distinct systems bearing the title moo duk kwan. Though the two Moo-duk-kwans are relatively similar in style and structure, and many Korean masters draw their lineage from Kee. The two Moo-duk-kwans possess differing forms and a somewhat differing focus upon self defense.

Tang-soo-do does not use the traditional Korean black belt in its ranking system. Kee believed that persons who wear a black belt believe that they are masters. Since the martial arts are a continual learning process, he felt that no one can ever truly become a master. Therefore, Tang-soo-do dans wear a dark blue belt.

When the Moo Duk Kwan had rank testings the Chung Do Kwan's Lee Won Kuk and Song Moo Kwan's Ro Byung Jik visited and built a good friendship, but regarding dan certificates and promotions they had disagreements with Hwang Kee.

The first Moo Duk Kwan dan holders were Kim Woon Chang, Hong Chong Soo, Choi Hui Suk, Yoo Kwa Young, Nam Sam Hyun, Kim In Suk, Lee Bok Sung, Hwang Jin Tae, Won Yong Bup, Chung Chang Young, and Lee Kang Ik.