If you have experience in other martial arts you may have noticed that many of their patterns are similar to Taekwondo patterns. It makes one wonder "Which came first?" I do not know enough about the history of all patterns to know which came first but the similarities of definitely there.
Some reject the premise that Taekwondo was influenced by Shotokan karate. Check out these photographs of Master Gichin Funakoshi, founder of Shotokan karate, performing the Pinan Shodan kata, which came decades before Taekwondo was founded. Compare it to the Won-hyo hyung of traditional Taekwondo. Notice any similarities? The pinan kata were introduced by Itosu, when karate started to be taught in the Okinawa schools. The name was changed into heian by Funakoshi when he came to Japan. Pinan Shodan is the first of these kata, it was renamed (and renumbered) into Heian Nidan.
General Choi, the disputed "founder" of Taekwondo, who originated the Changhon pattern set used by the ITF and many other Taekwondo organizations was originally a Shotokan karate black belt; for a time, he actually was a student of Gichin Funakoshi, the father of Japanese karate and founder of Shotokan. In a January 2000 issue of Taekwondo Times Magazine, Choi stated that he studied under Funakoshi while he was a student at Tokyo University. He also stated that upon receiving his 2nd Dan in Shotokan, he taught Shotokan Karate for a time at the YMCA in Tokyo. Choi's original Taekwondo espoused many of the core beliefs, techniques, patterns, and procedures of Funakoshi's karate.