Have you ever wondered why the last letter of the alphabet is pronounced “zee” by Americans and “zed” by most British, Canadian, and Australian speakers? The older pronunciation of “zed” was inherited from the Old French. The American “zee” is from a dialect heard in England during the 17th century and was approved by Noah Webster in his American Dictionary of the English Language (1828).
The letter z, has not always been at the end of the alphabet. In the Greek alphabet it was letter number six. According to Tom McArthur in The Oxford Companion to the English Language (1992), “The Romans adopted Z later than the rest of the alphabet, since /z/ was not a native Latin sound, adding it at the end of their list of letters and using it rarely.” The Irish and English simply imitated the Roman convention of placing z last.