Northrop Frye in "Our Modern Century" makes the case, if I can recall correctly, that most of the events that made the 20th century "modern" (such as Einstein's "e=mc²", Ibsen's "A Doll's House") occurred within a brief period of its first ten or so years.

And would you think of the end of the 19th century as a time of terrorism? 

Yesteryear's Terrorism
("Social Studies", Michael Kesterton, Globe and Mail, September 12, 2001)

"As the 19th century ended, it seemed no one was safe from terrorist attack," wrote Walter Laquer in the journal Foreign Affairs in 1996. In 1894, an Italian anarchist assassinated French president Sadi Carnot. In 1897, anarchists fatally stabbed Empress Elizabeth of Austria and killed Antonio Canovas, the Spanish Prime Minister.  In 1900, Umberto I, the Italian king, fell in yet another terrorist attack; in 1901 an American anarchist killed William McKinley, president of the United States. Terrorism became the leading preoccupation of politicians, police chiefs, journalists, and writers from Dostoyevsky to Henry James. If the year 1900 the leaders of the main industrial powers had assembled, most of them would have insisted on giving terrorism top priority on their agenda."

When the twentieth century, slowly turned into the 21st, our celebrations were largely muted under the threats of Y2K blackouts and threats of terrorism such as those that were uncovered in Seattle, Washington - threats that seems so unreal at the time.

It is the now the year 2001. The previous "Day of Infamy" has been remembered as just another romance and special effects film. 

Perhaps September 11, 2001 will be known as the true beginning to our new millennium.

"If you want peace, work for justice."