My question is: Is there a contraction for the phrase 'it was'? Would this contraction be 't'was'? - Thanks
'Twas on a Monday morning, the gas-man came to call...'. In the song 'The Gas Man Cometh', by Flanders and Swann, every verse begins "'Twas".
'Twould repay your reading the words if you are unfamiliar with it.
In contractions, the apostrophe replaces the missing letters. "He is" becomes "he's" where the apostrophe replaces the "i". "Cannot" becomes "can't" where the apostrophe replaces the "no". In the case of "it was", there are no letters between "it" and "was". The apostrophe replaces the "i" and the correct contraction is 'twas.
'Twas a good question. See the http://en.wikipedia.org/wiki/Contraction_(grammar) entry for "it" and you should also be able to find an entry for 'twas in your dictionary.