I have finally delved sufficiently into the matter to decide that the cynics are right, and neither Frederick Cook nor Robert Peary reached the north pole in 1909. Both were frauds. You can read John Tierney's summary of the evidence here. Tierney reports that the first human to cross the pole may have been Roald Amundsen, who floated over it in a dirigible in 1926. But the first undisputed claim to have reached the pole on land belongs to Minnesotan Ralph Plaisted, who traveled by snowmobile in 1968.
That Peary's claim stood up for so long is rather remarkable, given how flimsy it seems to me after reading something about the evidence. All of which goes to show that hype can be a very bad thing for science, as likely to lead to sloppiness and fraud as to real discovery.