What does the attorney say to you in the letter?
If you don't know the answer to this question, you likely need to brush up your knowledge of copyright law. The first question is whether or not your cousin's blog post/web site was subject to copyright protection? The answer is clearly yes under the definition of what works are protected and whether or not the work has been published.
Copyright protects “original works of authorship” that are fixed in a tangible form of expression. This definition applies to a post in Blog as well as to a hand-written letter. Publication is the distribution of copies of the work to the public. See Title 17 USC Section 101. Posting in a Blog comes under the protections of the Copyright Act.
Did the fact that you provided an attribution to the original source change the law to allow you copy the entire story? Unfortunately there is nothing in the copyright law that allows you to circumvent the law by simply providing a source citation.
Could you use a portion of the biography, rather than the whole biography? This is the question. There are a few assumptions made in the example above. I assumed that the cousin wrote the biography but if the cousin merely copied the biography from another source and claimed ownership that creates a whole different level of issues. If I change the facts to say that the cousin copied the story from an old 19th Century publication and didn't bother to tell the attorney where he or she got the article, then the discussion will get interesting. I will get into this topic further in this series, but the quick answer is that you cannot copy something from the public domain and then claim a copyright in the copy.
Back to the question of how much of the biography could you copy without running into a problem? There is no quick and easy answer. The law about using a portion of a copyrighted article is called the Fair Use Doctrine. Here is the statute:
§ 107. Limitations on exclusive rights: Fair useIf your use of a portion of the biography was for a commercial purpose, then you would have a greater restriction under the law than if you were using it for teaching, scholarship or research. The reference to "nonprofit" does not get you off the hook merely because you don't make any money, most of the references to non-profit in statutes like this refer to designated non-profit organizations under the U.S. Tax Code.
Notwithstanding the provisions of sections 106 and 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include —
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
(4) the effect of the use upon the potential market for or value of the copyrighted work.
The fact that a work is unpublished shall not itself bar a finding of fair use if such finding is made upon consideration of all the above factors.
What it boils down to is an argument about physically how much of the original document can be copied. Unfortunately that is one reason we have courts; to decide such issues.
Now what if your cousin lived in England, Scotland, Australia, Canada or where ever? Does that change the situation? Not much, if at all. The U.S. recognizes many, many countries copyright claims.
Here's what I suggest. Look at the same sources used by your cousin and write your own biography using your own words. Problem solved. No copyright claim. Further suggestion, when you write your own version of the story, don't try to use the same words, phrases etc. as those used by your cousin.
Remember, I will be teaching a class on copyright at RootsTech this next February.