Just uploaded to YouTube from Recollection Road...

[dth1971]

...is a video flashback to the events of the year 1970. At the 4:38 mark is mention of the launch of American Top 40 with Casey Kasem on July 4, 1970.: www.youtube.com/watch?v=ivmJwu8JTgk

[albe]

^^^They didn't use the Billboard Chart image but the listing from the oldradioshow.com