This is short but oh so sweet. It's William Daniels and most (probably) of the original Broadway cast of 1776 performing on The Ed Sullivan Show for October 4, 1970. 1776 opened at the 46th Street Theater (which is now the Richard Rodgers, which is where Hamilton is playing) on March 16, 1969. So it had been running a year and a half before its producers decided to let it be seen on TV. Back then, that probably meant the box office needed a boost.
But it seems to have worked. Soon after this performance, the show moved to the St. James Theater to make room for No, No, Nanette and later, it moved to the Majestic. It played there until it closed on February 13, 1972 after 1,217 performances…which was and still is a pretty good run.
It was playing there when I went to New York in 1970 and I still don't know why the hell I didn't go see it. I did a lot of stupid things when I was young — not to be confused with all the stupid things I've done since I became not young…