A、In 1776. B、In 1783. C、In 1808. D、In 1828. D细节题。文中明确提到，The American Dictionary of the English Language(《美国英语词典》)是在1828年出版的，故答案为

Language experts say that spoken English was almost the same in the American colonies and Britain. Americans began to change the sound of their speech after the Revolutionary War in 1776.[29]They wanted to separate themselves from the British in language as they had separated themselves from the British government.
    Some American leaders proposed major changes in the language. Benjamin Franklin wanted a new system of spelling. His reforms were rejected, but his ideas influenced others. One was Noah Webster.
    Webster wrote language books for schools. He thought Americans should learn from American books. He published his first spelling book in 1783.[30]Webster published The American Dictionary of the English Language in 1828. It established rules for speaking and spelling the words used in American English.
    Webster believed that British English spelling rules were too complex. So he worked to establish an American version of the English language. For example, he spelled the word "center: c-e-n-t-e-r" instead of the British spelling "c-e-n-t-r-e". He spelled the word "humor: h-u-m-o-r" instead of "h-u-m-o-u-r" as it is spelled in Britain.
    Noah Webster said every part of a word should be spoken. That is why Americans say "fac-to-ry" instead of "fac-try", as the British do.[31]Webster’s rule for saying every part of a word made American English easier for immigrants to learn. For example, they learned to say "waistcoat" the way it is spelled instead of the British "weskit".
    The different languages of the immigrants who came to the United States also helped make American English different from British English. Many foreign words and expressions became part of English as Americans speak it.
29. Why did the Americans change the sound of their speech?
30. When was The American Dictionary of the English Language published?
31 . What can we learn about Noah Webster?