I know this is a little old now but...being a SBD practitionerI figured I would chime in...here is a brief history lesson...
The first recorded usage of the term "Tang Soo Do" in contemporary history was by Chung Do Kwan founder, Won Kuk Lee. Most of the major Kwans called their style Tang Soo Do, or Kong Soo Do.
The Chung Do Kwan, along with the rest of the Kwans ceased using the name Tang Soo Do, and Kong Soo Do when they unified under the name Taekwondo. The Moo Duk Kwan, being loyal to Hwang Kee, pulled out of the Kwan unification and remained independent of this unification movement, and continued to use the name Tang Soo Do.
GM Hwang Kee organized the Korean Soo Bahk Do Association in 1945. In 1968, Master Jae C. Shin, who studied directly under Grandmaster Hwang Kee, founded the United States Tang Soo Do Federation which later became The World Tang Soo Do Association in 1982.
In 1995, the late Hwang Kee officially changed the name of the Moo Duk Kwan style to Soo Bahk Do.
Check out wikipedia...for more detail...
http://en.wikipedia.org/wiki/Tang_Soo_Do