The aircraft is now in exactly the condition it was on the day of its mission. After a $1m ( pounds 700,000) refurbishment that took 10 years, every bolt, rivet and pressure gauge is as it should be.
The museum hit trouble three months ago, however, when it unveiled plans for the exhibition for which the Enola will be the centre-piece. Entitled ''The Last Act, The Atomic Bomb and the End of World War II'' it is due to open next May. The Smithsonian found itself accused of insulting American veterans and falling prey to ''political correctness'' because of the attention it had paid to the Japanese side of the story. To the critics, the exhibition was about to portray the Japanese as blameless victims and the Americans as imperialists intent on taking revenge for Pearl Harbour.
The Smithsonian is still trying to navigate the mess; its efforts to compromise by excising some of the material sympathetic to Japan have only riled some historians, who are murmuring ''whitewash''.
Its misfortunes are just one battle in a much wider history war now rattling America's airwaves, editorial pages and common rooms. Reminiscent of recent debates in Britain, it centres on how history - and which history - should be taught in US schools. What triggered it here was the release this month of two sets of new national school standards, one for American and the other for world history.
Predictably, the debate has been cast as a battle between Left and Right. The unwilling, and somewhat bemused, occupants of the ''Left'' corner are the hundreds of teachers and history professionals from around the country who were recruited two years ago by the outgoing Bush administration to help compile the new standards to serve as voluntary guidelines for teachers. What they have come up with is a call for a new, progressive approach to history teaching, that rejects the ''dead men and dates'' approach in favour of involving the students directly in the subject, for instance through exercises and role-playing. It also suggests paying less attention to Western, European-based civilisations and more to more distant, but arguably equally important, societies such as the Olmec civilisation of Mesoamerica.
''Flush them down the toilet!'' railed Rush Limbaugh, the conservative radio talk-show host, delivering his verdict on the standards. Others of the same political hue responded similarly, if less bluntly. They complained about leftist anti-Americanism and the omission of many of the traditionally revered heroes of history textbooks - many of them American. Why, for example, was there no mention of Robert E Lee, the Confederate leader, or of Thomas Edison, the Wright Brothers and Albert Einstein, but 17 references to the KKK, 19 to Senator Joe McCarthy, who ran an anti-communist witch-hunt in the 1950s, and six to Harriet Tubman, who helped in the Underground Railroad for escaping slaves?
Pat Buchanan, the conservative commentator and 1992 presidential candidate, believes both the Enola Gay and standards affairs offer evidence that ''the Left's long march through our institutions is complete''. In a recent column, he wrote: ''Secure in tenure, they now serve up, in our museums and colleges, a constant diet of the same poison of anti-Americanisms on which they themselves were fed. Ultimate goal: Breed a generation of Americans who accept the Left's indictment of our country. For any nation to subsidise such assaults upon its history is to toy with suicide. But for Americans, whose history is so full of greatness and glory, it is criminal cowardice.''
The first shots came from Lynn Cheney, the wife of the former Bush administration defense secretary and possible 1996 presidential candidate, Dick Cheney. This is ironic because it was Mrs Cheney, as former chairperson of the National Endowment for the Humanities, who approved the funding for the standards project in the first place. In blasting her own progeny, she suggested the standards were ''politically correct to a fare-thee-well'' and queried the emphasis on non-European civilisations. ''There is too much that is too old. There's nothing wrong with studying the rest of the world, but not through this massive detail. There's gender relations in Gupta India, and students are supposed to read John of Plano Carpini on the Mongol threat.''
Expected to be endorsed by the Clinton administration in the coming months and incorporated in a new education policy, the standards are divided chronologically. In each era events considered of lasting impact are highlighted. ''Explain the development of tropical agriculture in South-east Asia,'' asks one. ''What role did bamboo play as a major tool in this area?'' Suggestions for classroom role-playing are also included. One asks students to ''role-play a discussion between an upper-class Hindu and a Muslim about their reaction to the British presence in India in the late 19th century''.
The co-editor of the world history standards, Ross Dunn of San Diego State University, says the time is long gone when history teaching was a matter of ''heritage-transfer'' in the classroom, ''emphasising the traditional hero and traditional political history''. That is what the conservatives still believe it should be, he says, while their aim is to scupper ''the standards entirely rather than engage in debate''. Asked about the reference to the Olmec civilisation, he offers no apology. ''I can think of all kinds of reasons why our kids should know about Mexico's history. Can't you?''
The notion of a leftist, politically-correct plot elicits a disgusted laugh from Michele Forman, a school teacher in Vermont, who helped compile the standards. ''That's just totally false. History has been evolving and the way it has been taught has been evolving and all of us are working more and more in multi-cultural classrooms,'' she counters. ''It's absurd to think we can go back to 19th century standards and turn our back on women in history or pretend that people who are not of European descent have no history.''
Doubtless the arguments over the Enola Gay will be ironed out and the exhibition will open on time. A watch retrieved from the rubble of Hiroshima, its hands frozen at the time of the blast, considered too pro-Japanese by some veterans, may even be reinstated to the exhibition, beside a more prominent record of the torture of PoWs by Japanese soldiers in Asia. The struggle for America's ideological soul, however, will be a long one.