Late 1960s: The Woodstock Music and Art Fair, one of the most famous rock festivals in history, is held August 15-17, 1969, on a farm in Bethel, New York. It is organized by four inexperienced promoters, who encounter massive problems when the festival draws ten times more people than they expected, taxing the available food, water, and medical resources. Still, despite these and other problems such as drug overdoses, most remember Woodstock fondly, and it quickly becomes a legend.

Today: Two Woodstock revivals—one on the twenty-fifth anniversary in 1994 and one in 1999—are also memorable, but for different reasons. The first revival features better organization, while at the second, a riot breaks out. However, both fail to live up to the legend of the original.

Late 1960s: In 1969, a group of Native Americans calling themselves the Indians of All Tribes seizes Alcatraz, the...