The turn of the century has always been a big deal for modern civilizations. One hundred years of life is quite large compared with the average 70 or so given to most. Because of that, people tend to look in trends of decades, rather than centuries or millennia. When it does come time for a new century, when that second digit rotates, as it does so seldom, people tend to look for change. Events tend to fall before or after the century, not on top of it, and United States history, particularly, has had a tendency for sudden change at the centu ....