1203 students in my class...Penn High School, class of 1977. And we were not the largest class to gradulate from there! The school held only 11th and 12th grade and housed its own vo-tech program as well as a planetarium.
The graduation ceremony was held on the football field (think mid-June and NO SHADE). It took 4 hours and all of the faculty to read the names. We had 12 valedictorians with perfect 4.0 averages (back then, you didn't get extra points for taking AP or advanced classes).
Names were done in alphabetical order and by the time we reached the "M's" it was a zoo on the field with people getting up and walking around, not to mention the bottles and whatnot that were being passed around.
By contrast, my college class had 230 graduates. There were more students in my high school than there were on campus!