Welcome, rmatheron!

Sesquicentennial is the only term I've heard for a 150-yr.
span.

Um--I rather thought we had our Bicentennial in 1976,
and France's, for Bastille Day, was 1979.
Allons, enfants de la patrie,
le jour de gloire est arrivee...
Oops, wrong anthem
for this country!