I have been fortunate over the years to have a couple Walt Disney World trips overlap with Animal Kingdom anniversaries. Thought since today was the 16th anniversary it would be a good day to look back.
First up last year, the 15th. The park had buttons, guidemaps, other merchandise, and a special opening ceremony to mark the occasion.
For more pictures and video from the festivities visit my full picture set from the day here: http://disneygeek.com/wdw/trip_reports/2013/2013_04_day_06.htm
For the 10th Anniversary in 2008 I missed the opening ceremony due to a delay at the airport as well as checking in that morning. I did make it to the park a presentation by Joe Rohde which was held in the Theatre in the Wild and features him talking about the creation of the park. Here are a couple pictures from, for more visit the full picture set.