First, there is no US curriculum. States follow different programs. Independent schools such as SSM (Faribault) are entirely independent.
UK curriculum works towards two public examinations - GCSE and A Level. US doesn’t.
UK university admission depends almost entirely on A Level results. US university admission depends on a number of factors, including record of grades during high school years, student essays, teacher and counsellor recommendations, results of AP examinations and SAT or ACT test scores.
It depends what the child is used to. Our curriculum is designed to promote creativity and a student’s ability to work for themselves and explore their own interests in order to prepare themselves for the adult regime of college.