It is needed for One official purpose. To Demonstrate that a man who went through life claiming to be from Kenya, is in fact actually born in the United States rather than having just a bunch of knocked up paperwork from the Porous back door border of that Democrat Island in the Pacific.
That is, if he wants to get on the Presidential Ballot. Fortunately for him, we have 50 States with Idiots for Election officials.
In 1990, Obama stated to the NYT, WashPo, Tribune and LAT (I'll give one link) that he was "born in Hawaii," and this fact was reported nationwide. Where are you getting this "went through life claiming to be from Kenya" bit from? Surely, you can't mean that agency bio blurb the year later -- the one where Obama's info was included in a pamphlet along with about 80 other authors and disseminated just to a handful a potential publishers?
Given that the year prior it had been reported nationwide Obama was born in Hawaii, the agency bit was obviously (as they have stated) a goof-up. ("Dreams," accordingly, says not one peep about being born in Kenya; an odd omission if that's the schtick Obama was trying to pitch).