I don't find any part especially boring, but the 1880s, 1950s, and 1990s were pretty much holding patterns, politically speaking.
I have no idea how anyone is including the 1830s, 1850s, or even....
Dude wtf. So much happened in these time periods. You just called Reconstruction, the Roaring 20s, the entire lead up to the Civil War, WW1, the Jacksonian Age, all boring. I honestly think you should read up on some of these times. That's basically 111 out of 116 years. You may as well have just said everything except the Civil War and WW2.