(Quoted from the official 501st website at: http://www.501st.com/about_us.htm):
"The 501st Legion is the world's definitive Imperial costuming organization. No matter where you live, the power of "Vader's Fist" can be felt through professionally organized charity, fundraising and promotional events featuring the "bad guys" of Star Wars. The ranks of the 501st Legion span the entire United States and over 21 countries worldwide, with numbers increasing on a daily basis."
2. Who are the 70th Explorers?
Members of the 501st who live in the states of Missouri and Kansas form the 70th Explorers Garrison. The origin of the 70th Explorers name is twofold. The first part of the name stems from a shared major interstate that runs through both states, I-70. The Explorers part of the garrison name is a reference to Lewis and Clark (specifically), Pony Express, the Wagon trains and the other western movement that went through both of the states. The 70th Explorers started out as a squadron of the Central Garrison on February 24, 2005 and then was approved by the Legion Council to form its own garrison on October 2, 2005 where they were required to complete a one year trial period phase to demonstrate that it can operate as an independent body. The 70th Explorers was fully approved as an official garrison on November 4, 2006 by the Legion Council. Visit the garrison website at http://www.70thexplorers.com.
3. How do I join the 501st?
The only requirements for membership are "ownership" of an accurate, complete, and professional-quality costume celebrating the Imperial (Dark Side) characters from the Star Wars films or its expanded universe sources, that the member is able to wear said costume(s) and that the member must be at least eighteen ( 18 ) years of age. After you have a costume that you feel qualifies for membership based on the above mentioned standards, there are three main steps that need to be completed in order to be accepted into membership for the 501st.
Step one is just to verify that you are over 18 years old because in order to join the 501st, you must be over 18.
Step two is where you fill out the online official 501st Legion Application to apply for membership (located here):
Step three is where you provide your imperial identifications to the GML (Garrison Membership Liaison).
Imperial identification pictures: You will need to have two pictures taken of you alone in your costume - one with your helmet on and one with your helmet off. The pictures must be of a high quality and must show the entire costume. No partial pictures taken at a con in a crowd, no photoshopped or altered pictures are allowed. They need to be raw, well lit, full length pictures - one with the helmet on and one with the helmet off. Again, please make sure you are standing against a plain background and that both pictures show you in the entire costume from top to bottom.
4. My costume doesn't look exactly like the ones in the movies because I want to be unique.. can I still join the 501st?
The 501st has standards in place for Star Wars imperial canon movie quality replica costumes so be sure to submit your pictures to see if they qualify for membership. No custom character costumes are allowed. Those costumes who do not qualify upon the initial application will receive feedback and tips on how to modify the costume to bring it in line with what is an acceptable canon, movie quality 501st costume.
5. I have a Jedi costume, can I join the 501st?
To join the 501st your costume can be Imperial, Bounty Hunters, Denizens of the Empire or other "bad guy" costume. Rebel costumers should join the Rebel Legion, our sister organization located at: http://www.rebellegion.com/.
Questions regarding membership should be directed to the GML at firstname.lastname@example.org .