American English has the more economical and phonetic spelling. Unnecessary letters are left out and words are spelled how they sound. An obvious example is the omission in AmE of the letter u in words such as color, neighbor, honor etc. Compare also the AmE words traveling, jewelry
and program with their BrE counterparts travelling, jewellery and programme. However, this rule does not always apply. For example, you would expect skilful to be the AmE spelling and skillfulthe BrE spelling, but unfortunately you would be wrong!