Below are the pictures of the first and second 727 built. The latter, depicting Boeing's livery, was kept by the manufacturer as a demonstrator until it was scrapped in 1978, while the first remained active with United Airlines from its delivery in 1964 till its retirement in January 1991. Since then, it's been part of the Museum of Flight at Everett.
Photo © Bob Garrard
Photo © Ralf Manteufel
In all,1832 (including the demonstrator) of these narrow-body trijets were built between 1962 and 1984 in four different variants. The 727has been the first commercial jetliner to reach the 1,000th delivery mark, in December 1973, with N474DA of Delta Airlines.
Fifty years after that historical day, many 727 are still plying the skies, mainly as cargo haulers or as private jets.
For more about the 727 see:
Boeing 727 family;
Boeing 727 Prototype-"First Flights" video;
and a thirteen parts report published in Flight International dated 9 May 1963:
1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13