When it comes to the differences in British English and American English spellings even brits get caught out occasionally. The main difference is that British English keeps the spelling of words it has absorbed from other languages, mainly French and German
Whilst American English spellings are based mostly on how the word sounds when it is spoken
English was introduced to what is modern day America in the 17th century by the British settlers. Since then the language has evolved and has been influenced by the many waves of immigration to the USA
The spelling of British English words were cemented by Samuel Johnson in what is considered to be one of the most famous dictionaries in the world. It took Johnson, and six helpers, just over eight years to curate the 40,000 words that appeared in ‘A Dictionary of the English Language’, which was publihsed in 1755
Similarly in America ‘A Compendious Dictionary of the English Language’ was first printed in 1806 and popularised the American English spellings that were being used instead of the British English spellings of words, such as color instead of colour
The author was Noah Webster who followed up the original dictionary in 1828 with his ‘An American Dictionary of the English Language’ which had over 70,000 words.
Here are some of the main differences in the spellings
:British English words ending in ‘our’ usually end in ‘or’ in American English