A right that is unalienable cannot be sold, surrendered, transferred or taken, not even with your own consent. A right that is merely inalienable can be given up the moment you agree to give it up. The Declaration of Independence uses the stronger word. Most state constitutions use the weaker one.
What this work covers
The Declaration of Independence holds it to be self-evident that all are endowed by their Creator with certain unalienable rights, and that among these are life, liberty and the pursuit of happiness. It then says why government exists at all: to secure those rights, deriving its just powers from the consent of the governed.
That is a much stronger claim than it first appears. Unalienable means incapable of being alienated, sold or transferred. It is not a permission slip issued by a legislature, and it is not conditional on good behaviour, on paperwork, or on the mood of an administration. It is intrinsic and inherent to the individual, which is precisely why it cannot be signed away.
Inalienable is the quieter word, and the more common one. An inalienable right cannot be transferred without consent, which means it can be transferred with it, actually or constructively. Rights of that kind are not inherent in a person. They are granted, and what is granted can be withdrawn.
This work sets the two words side by side, traces where each one sits in the founding documents and in state constitutions, and asks the only question that matters afterwards: which of the two is your government actually honouring, and what are you doing about the answer?