Not to downplay what whites did to Indians because it was truly awful, there was enough church burning to go around.
These are pre-war, during the rise of Know Nothingism, and I was going to post and ask, did the hatred really die out that fast, that Catholics could serve side-by-side, or at least in the next brigade, as Protestants who recently tried to burn their churches, and nobody cared? Humans are strange.
Philadelphia Nativist Riots
"Kensington [PA] erupted in violence on May 6 [1844] and started a deadly riot that would result in the
destruction of two Catholic churches and numerous other buildings. Riots erupted again in July, after it was discovered that St. Philip Neri's Catholic Church in Southwark had armed itself for protection. Fierce fighting broke out between the nativists and the soldiers sent to protect the church, resulting in numerous deaths and injuries.
Several Catholic churches were burned"
Bath, Maine Anti-Catholc Riot, 1854
"In the late afternoon the crowd marched to the church, began smashing up the pews, hoisted an American flag from the belfry, rang the bell, and set it on fire. After the church was burned, a smaller crowd of at least a hundred roamed through the streets all night. There is no record of attacks upon any Catholic persons. A year after the riot, on Nov. 18, 1855, the Catholic Bishop of Portland attempted to lay the cornerstone for a new church on the same site, but the congregation was chased away and beaten."
Newark, 1850s, Catholic Church burned
Several other riots with deaths are also listed, including an anti-Catholic militia regiment formed in the 1850s, 71st NY, that served in the war.
Mormon church burning and killing was also rampant until they got to Utah, but again, it settled down somewhat out there by the 1860s. I wonder if the country was just becoming more accepting of other religions by the war? Or if individual circumstances controlled individal hatred?