I'm not sure whether you are looking for a british or american speech pattern.
If it's american...

You may find the article at the link below interesting & the rest of the website is interesting if you are interested in the american civil war period. There is a section in the links area of the website about authentic speech.

http://www.authentic-campaigner.com/forum/showthread.php?t=1092

If you have access to JSTOR (perhaps through your library) there are a lot of articles about authentic speech patterns in the database.

If  you are trying to find information on an upper class british accent, you need to search for what is known as RP (Received Pronunciation) which is what it's called by linguists.

If you google it you will come up with thousands of articles.

Hope that is of some help :-)