Short answers, pulled from the story.
Albin Johnson created the Detention Block 2551 website in August 1997. This site featured photos of himself and his friend Tom Crews wearing homemade Stormtrooper costumes.
The tradition originates from a line in Star Wars where a character asks TK-421 why they are not at their post. Members receive individual identification numbers upon joining that become their number for life and never get assigned to anyone else after death.
George Lucas served as the grand marshal during the annual Tournament of Roses Parade in Pasadena California on the 1st of January 2007. Two hundred members of the Legion marched in this event while Lucas discussed the future of the rapidly growing club with founder Albin Johnson.
There are 76 Garrisons worldwide with the German Garrison being the largest unit containing over 1000 members. Garrisons require at least 25 active members and have no upward limit on how many can belong.
The 501st Legion announced their commitment to a first-of-its-kind international endowment in September 2016 through a unique partnership with Make-A-Wish. The goal was to reach $150,000 in the fund by 2021 to grant wishes from interest accrued for children diagnosed with life-threatening medical conditions.