It depends on what your native language is (or, if it's English, what your native dialect is). Accents come from different uses of sounds in different languages, so developing an American accent means eliminating the ways you say these different sounds in your native language and saying them how American speakers would. There are lots of resources online for adopting accents: one of my favorites is the voice coach Gareth Jameson's videos at videojug.com.
It really doesn't matter. Native English speakers (American and English) will be far more impressed if you have a good vocabulary and good use of grammar than if you have perfected a particular accent. As a native English speaker, I tend to assume that people who speak English as a foreign language adopt the accent of their teacher, or of the area that they learnt English in.
One word: practice. It is usually easier for young people to adopt an American accent. However, it is not impossible for an adult to eventually speak perfect American English with practice. You'll have to make conscious effort, though.
The Irish accent is generally considered closer to the English accent than the American accent, as both the Irish and English accents belong to the British Isles. However, the Irish accent has distinctive features that set it apart from both the American and English accents.
If you study American English, you would be taught to approximate the Standard North American English accent.
American/English
American came before English and our accent orignated of American
miley Cyrus is American but she can speak English because American people do speak English and miley Cyrus has a American accent
No, he didn't. (sorry.) he had a West Virgian accent. (i guess)
English - American accent though
Mary Draper did not have an accent. She was born in the American colonies in the 18th century, so she would have spoken English with a colonial American dialect, which was likely different from modern American accents.
I believe that in American English the accent is in the middle (the second syllable), while in British usage the accent is in the beginning of the word (the first syllable). American: lyooTENant. British: LYOOtnant.
possibly an English accent