Well, for some words there's weird little quirks, but for many of the changes Noah Webster decided to make improvements when he wrote his dictionary. Like Sulphur to sulfur and that sort of thing, but because it was done in an ad hoc way it wasn't consistent or driven by a singular aim (such as simplicity or faithfulness to the etymology),
Some words like faucet used to be used in British English but fell into disuse but continue on in America.
Aluminium originally was Alumium (coined by it's discoverer) then was changed to aluminum (which actually makes the most sense for technical reasons) but was renamed aluminium to be consistent with other elements but not with the consent of the discoverer.
Even though I think "mistakes were made" it's foolish to try to discard American English as just wrong which a lot of people try to do. If you start going back and undoing that sort of thing you'd have to go back much further. For example the word indict has a silent c in it because even though it was always pronounced "indite" because linguists knew it derived from the Latin indicere they deemed it should reflect that by having a c. So it was given a silent letter to show off in a way.
It should never have happened but that's the 1600's for you!