I was at the 1979 Epcot groundbreaking ceremony as a member of the media. To say there were 100 people there would be somewhat of a generous estimation. My best guess (a lot of years have passed) would be no more than 60-70 people attended.
The people attending the ceremony were loaded onto a bus and took a very bumpy ride over a makeshift dirt road through the Florida pine scrub. The destination was a small clearing in the woods where then-CEO Card Walker turned over a shovel of dirt as other WDW execs looked on. I still have the commemorative plastic hard-hat emblazoned with "EPCOT Groundbreaking" and the date, that was given to attendees.
When I returned for the opening-day ceremony of EPCOT Center (what it was called back then) in 1982, it was hard to comprehend what I was looking at once was wilderness.
Great memories, for sure.