Katie Couric's notebook: Civil War

150 years ago today, the first shots were fired in the bloodiest war in American history - a war that turned brothers into bitter enemies.

In a new Pew poll, 48 percent of Americans said the Civil War was mainly about states' rights, and just 38 percent said it was about slavery. Time clearly works like Mederma for the mind...fading an ugly scar of truth.

Lincoln's next line in that speech was, "I believe this government cannot endure permanently half slave and half free."

Slavery was a pox on the whole nation, not just the South. The war was really about attitude, not latitude.

The union stood because President Lincoln stood for what was right and the nation began a march toward equality as one.

That's a page from my notebook.

I'm Katie Couric, CBS News.