I love looking at old photographs and poking around in ancient books. If you’re as curious as I am about old stories, you might enjoy reading Allan Pinkerton’s action-packed adventures featuring Kate Warne. Look for The Expressman and the Detective (W. B. Keen, Cooke, 1874), The Somnambulist and the Detective: The Murderer and the Fortune Teller (W. B. Keen, Cooke, 1875), and The Spy of the Rebellion (G. W. Carleton, 1883).
I also think it’s fun to dig up old newspapers to see what daily life was like. Now that most newspapers are archived online, research has become easier. You can find great nuggets from history, such as the Chicago Press & Tribune description of the Pinkerton detectives threatening “genteel rascality” that ran on here. That account was published January 21, 1857, though I placed it a few years later in the book. I found the Amboy Times description of Abraham Lincoln as “crooked-legged” on July 24, 1856, to be hilarious (here). And I couldn’t resist updating the plot with the Chicago Press & Tribune story from October 2, 1860, that included mention of a “fine Glee Club” (here).
There are many websites that feature full transcripts of Abraham Lincoln’s speeches and writing. One of the most helpful sites I relied on was The Lincoln Log: A Daily Chronology of the Life of Abraham Lincoln. The site is part of the Papers of Abraham Lincoln, a project of the Illinois Historic Preservation Agency and the Abraham Lincoln Presidential Library and Museum. It can be found at thelincolnlog.org.
If you want books that aren’t more than a hundred years old, you can look through some recent nonfiction titles that examine this part of American history. Many are fast-paced accounts, not anything stuffy and boring. The best-researched books I enjoyed were Michael J. Kline’s The Baltimore Plot: The First Conspiracy to Assassinate Abraham Lincoln (Westholme, 2008) and Daniel Stashower’s The Hour of Peril: The Secret Plot to Murder Lincoln Before the Civil War (Minotaur Books, 2013).
Sometimes when you’re writing, you have to figure out the little details before you can capture the bigger picture. And that can make for some amusing titles to check out from the library, such as C. Willet and Phillis Cunnington’s The History of Underclothes (Michael Joseph, 1951) and Martha Vicinus’s Suffer and Be Still: Women in the Victorian Age (Indiana University Press, 1972). I also relied on Wendy Gamber’s The Boardinghouse in Nineteenth-Century America (Johns Hopkins University Press, 2007).