51 years ago Today, CBS broadcast their first ever half hour newscast. 

Since 1948,  the newscast anchored first by Douglas Edwards and then Walter Cronkite was just 15 minutes long.

On September 2, 1963, that newscast was stretched to a half hour.

Of course, if you count all the commercials and promos, some would argue that Today's CBS Evening News is still just 15 minutes of actual news.