> How did he get and maintain full control?
It's his company. When you make the company and give out shares, just get the lawyers to agree to allow you to keep control. Its just legal documents. If you have a good startup VCs and angels may be willing to give you better terms.
> Is it possible, as a founder, to maintain complete control of the board and the company through Series A - E ?
Sure. I've noticed several company IPO announcements on HN lately included the founder-control shares in their IPO prospectus, so it can't be too unique.
The way they do this is by having share classes. Eg Class A shares each gets x% of company and y% of votes. Class B shares get X% of company and [Y/20]% (or 0 sometimes) of votes. The 1/20 is arbitraty btw, it can be any ratio. Sometimes i see A, B, C shares where A is founder/vc tier with extra votes, B is "regular" with smaller votes, and C is no-vote shares, and often C is sold through IPOs into the exchanges.
I have no data on how common these different schemes are, but they're things ive seen in HN-announced start-ups and IPOs in the last year, so take that as anecdotal.