1) Anniversary 2) Bicentenary 3) Day of remembrance 4) Long-delayed celebration 5) The 200th anniversary 1) Bicentenary 2) Birthday 
• (a.) Consisting of two hundred years. • (n.) The two hundredth year or anniversary, or its celebration. • (a.) Occurring every two hundred years.
Bi`cen·ten'ni·al adjective [ Prefix bi- + centennial .] 1. Consisting of two hundred years. 2. Occurring every two hundred years. 
[adj] - of or relating to or completing a period of 200 years 2. [n] - the 200th anniversary
bicentenary adjective of or relating to or completing a period of 200 years; `bicentennial celebration`
pertaining to or in honor of a 200th anniversary: bicentennial celebration; a bicentennial exposition. · consisting of or lasting 200 years: a bicentennial period. · occurring every 200 years: the bicentennial return of a comet.