White America Policy?

Just browsing stuff and came across a list of requirements to become a US Citizen. One of them is:

you must demonstrate an elementary level of English (reading, writing, understanding); Is this right? I always tend to question legal advice from random websites, and this one seems to have the entire purpose of getting you to find a lawyer using their site… If this is right, how is this different from the extremely controversial, and now removed, White Australia Policy? Finally, is it really the case that every American immigrant speaks english? That would suggest to me that there’d be effectively noone in the US that didn’t speak English as I’d imagine someone born in the US would pick up enough over their lifetime to speak at least “elementary english”. There’s still a few exceptions – people born in the US and moved overseas at an early age etc – but that would be an extremely small percentage of the population I’d imagine. Any Americans want to shed some light on this?