George Bernard Shaw is supposed to have said ' England and America are two countries separated by the same language', but there are other claimants and versions of this. It doesn't matter, the substance of it is the same.
The early British settlers (migrants?) took their language with them, but it was very different to the English we use today. Languages aren't static and English has continued to evolve on both sides of the Atlantic and at local levels. It can be a bit irritating, per many of the examples in this thread, but I don't have any real problems with it.
I spent some time in India a few years ago and it's still quite common to meet Indian people who speak English with hints of the 'Raj' in it. I still have a newspaper which I kept, because I loved the short article about a street robbery, which ended with 'the police caught the wicked rascal in the small hours of the morning...'