I do remember the plans for the 1976 Worlds Fair. It was to be located at Pleasure Bay in South Boston.
As far as Boston being a dump in the 1950's, I totally disagree. I was born in 1949 and lived in East Cambridge until I was 5. I loved it and still even dream about it. It was the perfect urban neighborhood at the time: virtually no crime, great neighborhood stores of every kind, well-maintained housing; just a a beautiful, dense neighborhood. It was a very different world back then. The downtown Boston shopping area (Washington and Summer Streets) was a magical, exciting and wonderful place. The Boston and Cambridge neighborhoods were safe and vibrant, factories were humming, family wage jobs were plentiful, housing was affordable, traffic was manageable, and the future was full of hope for working class people, including Blacks. It's funny how this Boston 2100 thread has turned into Boston 1950, but in some ways that makes sense, as the keys to the future lay in understanding the lessons of the past.