I’m 68 - just 3 years older - and the only graduation was from high school, my senior year. I did not attend kindergarten; went directly in the 1st grade before I turned six. We had elementary schools - grades one through six. Went directly to junior high - grades seven through nine - with no graduation. Middle school was not conceived of back then. Did 3 years of senior high school - grades ten through twelve. Only after finishing my senior year was there a graduation. Holding graduation from kindergarten, from elementary school, from middle school, is bravo sierra.
I graduated a Baptist Church kindergarten in 1969. Cap, gown, the whole 9yds. That was it until 12th grade.
Structure at the time was;
Elementary 1-6, Junior High 7-9 and HS 10-12.
Knoxville, TN