1970: The Arbor area is created with a Garage Door and Tire Swing. There is now a Briefcase by Oscar's Trashcan and not a box. Big Bird now has his own Nest and his Nest Area which is full of colored barrells. 1973: The set has a somewhat different look to it. It looks a little more colorful now. 1974: Oscar seems to take on a newer look. He looses that Bright Toxic Green color and that puffy look and his fur becomes more madded down and slightly darker. Also there is now a Brown Box by Oscar's can instead of a briefcase. 1978: The Briefcase by Oscar's can comes back. 1979: The Briefcase by Oscar's can disapears once again and the Brown Box used from 1974-1978 is back and this time to stay. The New Fix it Shop is built. Ironically from 1979-1988 there wasn't really any changes made to the set. 1988: The Colored Barrels are now gone from Big Bird's nest area. 1989: Hooper's Store gets a New Sign. 1991: Hooper's Store is rebuilt 1992: The set moves from Manhattan to Queens, and gets a brighter look. 1993: The Around the Corner set is created, and Big Bird's nest area now leads into the around the Corner area and not just a brick wall with the Alphabet on it. 1995: The No Parking Sign on the Garage door is gone. Gina opens up a Daycare center in an empty building in the around the corner area. 1998: Hooper's store changes it's look. It is now Sky Blue, and the around the corner set is gone. 2002: Hooper's store is now red, the Stairwell in the arbor area is red not Green and same with the doors of the 123 Building. Oscar now has shapes in the back of his can in the walls that seperate his can and Big Bird's nest. The Mail it Shop replaces the Fix it Shop, which was part of Sesame Street for exactly 30 years. 2004: The Doors are back to their old green color again 2006: The Stairwell in the Arbor area is back to green once again. The Fix it shop is back, and the shapes behind Oscar's can are gone. (Things are looking up once again for us classic fans!) If anyone has anything to add to this please do so. I'm sure there were more changes to the set over the years I just cant think of anymore at this time.