Modern history of East Asian martial arts
Taekwondo was developed from karate for use in the Republic of Korea Armed Forces from 1954. For this purpose, karate terminology needed to be "nationalized". The name "taekwondo" is due to shotokan practitioner and army general Choi Hong Hi. After the Korean War, Taekwondo was further developed into a purely sportive discipline, since 1973 overseen by the World Taekwondo Federation. 
During 1964-1966, Choi Hong Hi continued to promote taekwondo, working to put together a world-class exhibition team. Taekwondo's emphasis on jumping and flying kicks dates to this period. While taekwondo was based off karate, the structural changes made in the 1950s and 1960s were significant, and it cannot now be considered a branch of karate, but is a standalone modern martial art. Taekwondo was presented at the Summer Olympics as a demonstration sport in 1988 and 1992, and became an official Olympic discipline in 2000.
Tae-hong Choi
Choi moved to Washington, D.C., in 1971. He taught taekwondo to secret service agents and CIA operatives. His family did not move with him to Washington, D.C., but they emigrated to Oregon where a distant cousin lived. In 1972, Choi joined his family in Oregon and started teaching tae kwon do at the YMCA, Lewis and Clark College and Reed College (Judo - '74-'75), and Sunset High School before opening his own studio in Northeast Portland. Choi's Taekwondo Academy was the first taekwondo school in Oregon. 
"Mr. Choi was one of the pioneers for tae kwon do in this country. When the word 'tae kwon do' didn't even exist in this country, he was already teaching." -- Joon Pyo Choi, co-chairman of USA Taekwondo's martial arts commission.