Why do Americans spell ‘centre’- center or ‘theatre’- theater?

Ever wondered why Americans spell ‘centre’- center or ‘theatre’- theater?

This was due to an American named Noah Webster, who in 1783 compiled a dictionary with revolutionary changes in English language spellings. He was the one who created words like ‘barbecue’ and omitted ‘u’ from ‘dialog’, and ‘honor’ etc. It’s known as ‘Webster’s Dictionary’ and is still very popular.

- S.Yunus