[header] How to write accurate dialogue in historical fiction [title] Read primary sources to familiarize yourself with the time period. [step] In order to get in the mindset of writing for your time period, read letters, journals, and other types of personal communication. [substeps] Take note of the differences you see between that era's dialogue and modern dialogue. 
Reading these works will inherently train your subconscious to identify and utilize historical constructions in your writing. [title] Watch period television shows and commercials to acquaint yourself with more recent time periods.