Any and all documents produced in the 1700s/1800s are well out of copyright.
This is not entirely correct. Prior to the 1988 Copyright Designs and Patents Act, unpublished works* (except photographs) were treated as a separate case in which they remained in copyright until they were lawfully published. In theory this could mean that an unpublished work, such as a private letter or diary, could remain in perpetual copyright. The 1988 CDPA addressed this issue by stipulating that all unpublished works in existence before the Act came into force would be protected for a further 50 years then lose their protection. The Act came into force in 1989 so all affected copyright works will have their copyright end on 31 December 2039. As good family historians, we should always quote our sources and in this case it's CDPA 1988 Schedule 1 paragraph 12 sub paragraph (4). To save you looking it up this is what it says:
(4) Copyright in the following descriptions of work continues to subsist until the end of the period of 50 years from the end of the calendar year in which the new copyright provisions come into force—
(a) literary, dramatic and musical works of which the author has died and in relation to which none of the acts mentioned in paragraphs (a) to (e) of the proviso to section 2(3) of the 1956 Act has been done;
(b) unpublished engravings of which the author has died;
(c) unpublished photographs taken on or after 1st June 1957.
The reason photographs are dealt with separately is because, following the 1911 Copyright Act (
section 21), all photographs were protected for 50 years from the date they were made, irrespective of whether they were subsequently published or not. This also changed with the passing of the 1988 CDPA and photographs then became subject to the same rules as other types of work.
All works made after 1 August 1989 are subject to the standard copyright term of the lifetime of the author plus 70 years from the end of the year of his/her death.
Copyright is heritable. If there is no express statement in the will of an author or artist about what was to happen with their copyright in any unpublished item, it would have passed along with the physical article (a painting, diary, letters, unpublished manuscript etc) to the person who inherited the article (see
section 93 CDPA).
If the person who inherits the unpublished work decides to publish it, the copyright period will then run for 25 years (see Regulation 12 of the
Copyright and Related Rights Regulations 1996 (SI 1996/2967). And so if you have legally published a work of this sort (that is, any kind of work subject to copyright other than a photograph), you can legally put a copyright notice on it, and contrary to what has been said here, it is not in the public domain, even though it may be freely viewed by anyone.
Finally a point about exceptions to copyright. Many of you will know that it is permissible to copy and in some cases republish small extracts of copyright works provided this is solely for the purpose of private study and research (see
section 29 CDPA). This is one of the very few exceptions which does not require that the work being copied must first have been made available to the public. What this means is, if you have access to an unpublished work, but you are not the copyright owner by virtue of inheritance, you may still copy a proportionate amount of the work for your research purposes and you may publish that copy provided that this is for non-commercial purposes. To take an example, publishing your copy made under section 29 along with a tree on Ancestry, or on a forum such as RootsChat, is permissible, but publishing the same thing in book on genealogy which is then put on sale would not be lawful.
This is the position under UK law. Much of the same applies in Canada, Australia and New Zealand, but the law is entirely different in the USA or elsewhere within the EU for example.
*'Works' here refers to literary, musical, dramatic and artistic works. Films and sound recordings fall under an entirely different set of rules. So if you have inherited Uncle Harry's 8mm home movies, none of this applies to them.