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From "The First Dynasty of Islam: The Umayyad Caliphate AD 661-750" by G. R Hawting:
It seems likely that it was not until the later part of the Umayyad period that traditions, religious or historical (and the distinction is not always clear), came to be committed to writing with any frequency. Before that time they were generally transmitted orally in short, separate reports which were self-contained and relatively easy to memorise.
However, the same book suggests interesting data could be find in contemporary poetry (e.g. Farazdaq and Jarir). A little bit more on this can be found in "The Politics and Culture of an Umayyad Tribe: Conflict and Factionalism in the Early Islamic Period" by Mohammad Rihan.
Hope that helps.