You can bring one item from history to the present. What are you getting?

The cache of letters from her husband that Martha Washington burned before she died.

Ditto Eliza Hamilton, when she removed herself from the narrative.

An intact copy of the Q Gospel, if it indeed existed.

Good one.

But how about Portrait of a Young Man by Raphael. Nazis stole it, never recovered.

That was my vote, too.

My first thoughts were to raid the Library of Alexandria and the Antikythera mechanism. Though I’d want to examine the mechanism first to see how many parts are missing to decide if it’s really needed.

Mechanism recreation by one of my favorite Youtubers for anyone interested.

The problem with bringing it forward is that we would simultaneously destroy any value because it would no longer be an ancient artifact. Just an interesting brass mechanism created using ancient techniques.
Carbon dating wouldn’t work either because of the time-skip.

Nice, I’d forgotten about that story but it fits the topic perfectly.

I think there are things we could learn from it if we had it intact. It is an unusually modern-seeming mechanism for its vintage. If it had been presented completely out of context, I believe most people would have placed it as a post industrial revolution artifact.

If we had it in good condition, there’s a lot that could be learned and inferred from tool marks, consistency of shapes of objects and so forth.

Along the lines of the Library at Alexandria, where we know lots of stuff was destroyed but don’t know exactly what, I’d like to rescue some of the stuff burned in Savonarola’s bonfire of the vanities. In particular any books or manuscripts, to see what they thought was so scandalous.

I remember the story, but not the name or author. It wasn’t Lewis Padgett, was it?

Off the top of my head: Isaac Asimov, ‘Button, button’.