Many of the differences between American and British English date back to a time when spelling was not widely standardized. For instance, some spellings seen as "American" today were once commonly used in Britain; and vice versa. A "British standard" began to emerge following the 1755 publication of influential dictionaries such as Samuel Johnson's A Dictionary of the English Language, and an "American standard" started following the work of Noah Webster, and in particular his An American Dictionary of the English Language.