Although slightly different results had a similar ideal team in mind- https://community.cbr.com/showthread...=1#post3308904
in the order they joined:
(1961) Green Arrow Justice League of America #4
(1962) Atom Justice League of America #14
(1964) Hawkman Justice League of America #31
(1969) Black Canary Justice League of America #74
(1973) Elongated Man & Red Tornado Justice League of America #105-#106
(1977) Hawkgirl Justice League of America #146
(1978) Zatanna Justice League of America #161
(1979) Black Lightning* Justice League of America #173 *although he hadn't joined at the time in the 80s he was the next to join in the JL newspaper strip.
Yeah I skipped tornado
And to extend to 10-12 here I'd add Vixen, Vibe and Star-Light Kimiyo Hoshi, Steel.