“ARRL is the national association for Amateur Radio in the US. Founded in 1914 by Hiram Percy Maxim as The American Radio Relay League, ARRL is a noncommercial organization of radio amateurs. ARRL numbers within its ranks the vast majority of active radio amateurs in the nation and has a proud history of achievement as the standard-bearer in amateur affairs. ARRL’s underpinnings as Amateur Radio’s witness, partner and forum are defined by five pillars: Public Service, Advocacy, Education, Technology, and Membership.”
From the ARRL web page.