Ever since Wilbur and Orville launched their Kitty Hawk people have wanted to learn how to fly. (To be fair hey wanted to learn how to fly even before that). The military was one of the best ways to learn but after the wars are over there wasn’t much call for fighter pilots. So the ICAO was formed in 1944 for those civilians who wanted to fly. In 1994 the organization celebrated it’s fifty year anniversary and in 1996 it was recognized by US Congress resolution officially.
How to celebrate – Learn how to fly. Study the history of flight. Become a member of the ICAO.