The party in this photo is actually for the launch of Apollo 11. One million people, give or take, showed up at Cape Canaveral to watch the launch in 1969.
Buzz Aldrin describes this scene in his book about the mission, Magnificent Desolation. On the morning of the launch he was dropped off on the gantry of launch pad 39-A, 300 feet high, while the launch team loaded Neil Armstrong and Mike Collins into the capsule a few levels up.
Three and a half hours before liftoff, and for 10 minutes Aldrin is left standing by himself with nothing to do but sightsee.
Here’s how the scene looked to him:
The sun had not yet come up and was barely peeking above the horizon as I stood on the grating and peered through the clear bubble helmet I wore. The only sound I could hear came from my ventilation unit.
Looking up and down the coastline, my eyes scanned the beaches for miles along the causeway near Cape Canaveral, where more than a million people had started gathering the night before, trekking in cars, motorcycles, pickup trucks, campers, and large motor homes, inching their way through bumper-to-bumper traffic as they sought the perfect launch viewing location. Already people were filling in every available spot of dry ground, and thousands of boats were anchored on the Indian and Banana rivers near the Cape.
Without a good set of binoculars, most of the spectators could not see me, and from my vantage point I could barely see them, but I could see the evidence of them in the flickering campfires that dotted the beaches in the pre-dawn darkness. Everyone knew that something big was about to happen.