GCSEs and A-Levels in the US

As a UK student, a highschool junior equivalent, who is looking to study in the US at university level, (I’m prioritising US universities over UK ones), and I was wondering whether US colleges value grades at GCSE, A-Level and at SAT/ACT equally, or at different tiers like they do in the UK.

Thanks!

They will consider your GSCEs more than British schools would. You need to score well on the SAT/ACT, but your A-levels are more important.