The initial expectations for fusion were even more ambitious and with good reason. Fission was first done in 1938, by 1956 there was a commercial reactor. Giv

The initial expectations for fusion were even more ambitious and with good reason. Fission was first done in 1938, by 1956 there was a commercial reactor. Given that sort of time frame and the fact that fusion research was well underway it seemed that a decade or two was all that was needed. Then you had breakthroughs with Tokomaks and so on, each time it seemed that fusion was potentially close. There's a really good book called 'The Sun in a Bottle' that goes into more detail.