 A large number of the specimens in the National Philatelic Collection have great value and, in 1986, the curators of the collection refused to participate in Ameripex 86 – described by "Linn's Stamp News" as "one of the greatest international stamp exhibitions ever held" – after show organizers refused their requirements that stamps from the collection be housed under bulletproof glass and assigned a dedicated force of guards.In 2005, the United States purchased the boyhood stamp album of John Lennon to add to the National Philatelic Collection.There have been eleven curators of the National Philatelic Collection.