Bringing my household goods to the US

HI! I'm a Canadian citizen and US
green card holder. Also married
to a US citizen.

Since our house is smallish, I
left some furniture, books and
other stuff back in Canada.
Everything owned by me for years!
Now we want to go up, rent a
U_Haul and bring it all down.

What customs declarations do I
need at the border? The US
customs website only gives
advice on unaccompanied goods,
and the appropriate form for
that. But we'll be moving the
goods ourselves.

Thank you so much!

Basically you just tell them it's personal effects, present a manifest, especially helpful if you had it on a manifest they signed off on when you originally entered. In theory they might want to get you to pay duty because you're already an LPR but imx CBP are pretty laid back about it.

You actually have up to 10 years after your first entry to the US with valid visa to import your personal goods duty free.

If all your stuff is with you in the U-haul there is no particular CBP form. Just have a typed or written list itemizing the contents of all the boxes.

You actually have up to 10 years after your first entry

But I think you have to declare it when you entered initially. E.g. a manifest that says "goods to follow".

I have to say though that CBP never seem that bothered about personal effects. If it's a pile of junk in a U-haul I can't see how they could assess duty anyway, it would be valueless.

No, I dont think you do have to declare it on your first entry. I could be wrong of course, but I'm sure a former US CBP employee has told me that before.