SWPA was an American and Australian effort. When the war finally ended, the documents were divided between the US and Australia. Generals MacArthur and Blamey agreed that scholars of both nations would forever have access to both collections.
I very much doubt that they had any legal authority to make such an agreement but the fact is that the undertaking has been honoured, in Canberra, and in Washington.
Took a month off work. Travel to the US involves a long air flight across the Pacific. Security at Los Angeles is chaotic and delays are extensive. had to change planes in LA and St Louis before arriving in Baltimore. Rhonda said she had a friend in the Washington area called Tami who would put me up. I was a little chary about people volunteering friends but Tami said it was okay, but she wasn't getting rid of her kids or her cat to give me peace and quiet, which is fair enough. Her kids turned out to be charming, and the cat was a hoot.
From her place, I would drive around the Beltway to College Park, MD. The traffic moves fast there, about 70 mph minimum. Canberra traffic cops would have a field day, setting up speed cameras and automatically mailing out fines by the thousand each day.
The archives are in this modern glass building. As in other US Government buildings, security is strict. They don't let you take notebooks in! So I used the laptop. It has a dicky battery and I was afraid security would ask me to switch it on to prove that it works. And they let you do your own photocopying, for much less than they charge back home. They use this 18 inch foolscap size. Every page has to have a declassification tag on it, or the security guards will take it off you.
The files are not computer catalogued, much less digitised. And they are in the original form, having not been refiled. The US Army used a kind of Dewey Decimal filing system. Instead of constantly fetching files like they do in Australia, there are a few "pulls" each weekday - none on Saturday. The idea is to get requests into each pull so you don't run out of files. You can have a whole trolley worth of boxes, which is good, but can go through box after box very quickly. Anything vaguely interesting got photocopied.
I only looked at files related to 1943-44. Those for the Final Campaigns await another trip next year.