Costa Rica, 13th June 1921, Alajuela, Costa Rica
https://en.wikipedia.org/wiki/Costa_Rican_Football_Federation
Serbia, 28 August 1920 (first int'l game) but founded in 1919, Belgrade
http://www.uefa.com/insideuefa/member-associations/association=srb/index.html
Brazil, 20 August 1914...