1977 and I was 15. We went for my sister's high school graduation. We have a literal convoy of vehicles going from Pennsylvania - two of my aunts, a couple of cousins, two sets of family friends. That was 35 years ago but I still remember the details so well. How my dad marveled at Fort Wilderness (and we had been camping my entire life), how we went to Magic Kingdom that first day with the warning that we would only visit and be back at the campsite for dinner. We didn't get back until 2:00 AM! The swan that visited us every day at our site. Even singing "Looks Like We Made It" over the CB radio (it WAS 1977 after all) when we pulled into Fort Wilderness.
I've been to Disney World so many times and some details have faded but none, absolutely none, have left my mind from that first trip.