Consider this journal article by John Maynard Keynes, a British economist who died in 1946 (the article in question was published in 1943). The journal (still published) is based in the UK, and thus, it should be subject to UK copyright law.
According to UK law, the copyright of the work expires 70 years after the death of the author. For the case of Keynes, that is 2017. Similarly, the layout of the published edition has copyright for 25 years only. Thus, both copyrights have already expired.
However, the article (and many other articles in a similar situation, as the journal was created in 1891) are not freely available. They can only be accessed through JSTOR, as all links redirect to it (e.g. this and this). JSTOR does not allow free access (as in freedom of speech), albeit has a restricted form of free access (as in free beer), after registration, only for three articles and lasting 14 days.
Why does the publisher do not release the material to the public domain if the copyright has already expired? Do they have any obligation to do so, or it is a matter of active individuals/organisations to "exercise" that right? As such, can I request to them to give me access for free? As far as I understand, as a British resident (?), I am myself "entitled" to make that work available in the public domain, without infringing the copyright of the author or publisher.