PS: I've just noticed the word 'relocate', rather than 'visit', in your post.
I suspect that, if you're seeking to move to the USA, rather than to simply visit as a tourist, you'd find it exceptionally difficult (if not impossible) to do so. Firstly, you need to have specific grounds for doing so (such as being able to provide a service that US citizens can't do just as well, like professional sportsmen and internationally-acclaimed movie stars, or family ties). The vast majority of people from the UK (and from other countries where the USA's green card immigration system isn't available) simply aren't eligible to take up residence in the USA.
Friends of mine were eligible to move to the USA because they'd got close family there. However it still took them 2½ years to clear all of the hurdles of the US immigration system (and that was without having any problems such as yours with the Canadian authorities).