That's an assertion, to be sure. Others might not agree.

You are only allowed to disagree if you have a nonstandard definition for inalienable.

Hmmm, so the idea of natural / inalienable rights was developed by humans?

Discovery would be a better word.

For Southern Baptists during the Civil War era, God didn't consider enslaving Africans to be wrong. They weren't subject to the same inalienable rights as the white man.

Yes they were. Their tyrants are probably burning in hell right now.

Further back, during the Crusades, God didn't care about non-Catholics, they didn't have the inalienable right to life. Well, at least that's what the Catholics claim God's view was.

If the Catholics performed deeds that were contrary to the will of God and claimed God's name while doing so, they also get to burn in hell. However, I would postulate that the crusades were probably justified and in line with God's plan. That's for God to decide.

Just because it's possible to infringe a right doesn't mean the right doesn't exist. You have a right to life. If someone kills you, they violate your right, it doesn't mean the right doesn't exist. But yes, perhaps 'cannot' is the wrong word to use, maybe 'shall not' is a better term.

Under your model, it's possible to deprive someone of their inalienable rights without consequence. Under my model, depriving someone of their inalienable rights is punished. So who's model for rights sounds more "inalienable?"

How many Christian abolitionists were around in the 1500s or earlier? Surprisingly few.

How many slaves were there in the 1500s? Literally dozens!! The abolitionist movement didn't even start until 1688.

I don't think an infallible God would slaughter infants, sorry. I don't think an omnipotent God would need to, either. A Bronze Age tribe justifying their crimes by saying "God told us to", yes.

Once again, God gets to decide.

Why is that ironic? If one embraces the position that there is no absolute, objective, authoritative standard to pronounce something wrong, then that means that a subjective, consequentialist standard can pronounce something wrong.

Until another person with subjective moral standards hits you in the head with a rock. You will criticize the bronze-age tribal warriors for killing a few babies but refuse to account for the policies you still support in the present day and age. You've killed more babies by voting for democrats then the Israelites did, I guarantee you. That's where the irony lies.