Read all about it.
Track down as many primary sources as you can—sources written or created during the time period you’re studying: journals, diaries, autobiographies, news film footage, interviews, photographs, speeches, books (both fiction and nonfiction), research data, even art. I still remember the afternoon I spent at my local university library looking up old newspaper clippings from the early 20th century when I was researching Victory Garden. It was fascinating to see what had been written between the years 1917-1922, the days when the women’s suffrage movement, World War I, and then Prohibition were happening. I was also fascinated to see how propaganda was used then, which wasn’t so different from the way it was used during World War II. Here’s a funny thing you learn when you’re researching history: the more things change, the more they stay the same. I even enjoyed reading advertisements from the period because it gave me a sense of the culture then. On the surface everything appears so naïve and innocent in the early 20th century, the Coca-Cola ads, the blemish cream ads, the shaving cream ads, especially when compared to today’s commercials, but looks can be deceiving. Reading primary sources gives you a finger on the pulse of the times. What were people thinking and feeling then? As writers of historical fiction, it’s our job to find out so we can share it with our readers.
You can also read secondary sources such as books by historians, biographers, and social critics about your time. Read other historical novels set during the time too. Read it all. Even if most of the information doesn’t end up in your novel (and most of it won’t), it’s knowledge that will act as a backbone for the information you do share in your story. What you know will inform your writing, and the more of an expert you become through your research, the more expertly you will carry your readers into your chosen historical era. As writers of historical fiction, it’s our job to paint the scene of days gone by for our readers to visualize and understand. The more of an understanding we have about the era, the more interesting we can make it for our readers.