rain in the archives
Hodgdon, Max R., Papers, 1912-18, documents plane modifications in WWI to cope with rain and mud.
Rogers, Alonzo R. Papers, 1861, 1888, includes a letter to "Sister" from Alonzo in Camp opposite Chattanooga (Tenn.) dated Nov. 6, 1863 describing rain, homesickness, constant skirmishes, food and leaving for Bridgeport.
Young, Charles B. Correspondence, 1864, 1865. His last letter to "Dear Family", dated Dec. 22, 1864, notes that his comrades drove Rebels farther back, captured troops and artillery, were on night manuevers, the battlefields were covered with dead and wounded soldiers, rain soaked supplies, that he has been sick.