Founded in 2000,[2] the group was formed in response to the decision of sister organization the 501st Legion to remain dedicated to Galactic Empire costumes.

It is divided into "bases" located throughout the world, and as of November 2019, the Rebel Legion membership is approximately 8,000 members.

This prompted 501st members Tony Troxell, Richard Fairbrother, Ed O'Connell, Ken Ograyensek, and Doug Fesko to create a separate "Rebels only" costuming group, officially announced to the 501st Legion forums in December 2000.

Members regularly participate in events to raise awareness of charitable causes, from walk-a-thons to blood drives.

If an event host does not have a charity of choice, Legion members usually provide a suggestion, sometimes tied to a fundraising effort that is already underway.