This article briefly touches upon the La Niña which occurred during the Civil War, and it made me conscious of the fact that weather must have played a part in some of the war’s big events. (Meade’s failure to chase Lee on July 4th comes to mind.) The only book I could find on the subject looks a little dry (pun intended), and only deals with Virginia. I’ll have to search for some other resources on the topic; my interest has been piqued.

The new research used tree ring data to reconstruct the influence of El Niño and La Niña conditions on droughts across North America for the past 350 years, including during the American Civil War.   The Civil War drought – one of the worst to afflict the U.S. in centuries – occurred in the mid-1850s to the mid-1860s. That drought is infamous for its effects in the U.S. Southwest and parts of the Great Plains, where it led to the near extinction of the American bison and played an important role in changing

Source: La Niña’s Effect On Droughts Traced To U.S. Civil War | Los Alamos Daily Post