You named Presidents from the great American historical blind spot (we know Revolution, Civil War and pick up our history again around 1900 . . .). Apparently little happended between 1820 and 1900 other than the Civil War . . .
For example, well before the Civil War, Pierce took us effectively from Louisiana to the Pacific Ocean hiding (some believe surrepticiously) the news of gold at Sutter's Mill until the Mexican government completed the Hidalgo treaty, all in 1848-49.