The regiment that Lt. Pfeiff was in joined up with a whole bunch of other regiments, and they formed the Army of West Tennessee. Their commander was Major General Ulysses S. Grant. They went down into the south part of Tennessee, to a place called Pittsburg Landing, on the Tennessee River. While they were there, the Confederates, whose leaders were Generals Johnston and Beauregard, made a surprise attack on them, and there was a huge, bloody battle. The battle was called the Battle of Pittsburg Landing or the Battle of Shiloh.
During the Battle of Shiloh, about 23,746 soldiers died, and 13,047 of these were Union troops. Sadly, one of the dead soldiers was Louis Pfeiff.
Then Mrs. Pfeiff asked for the grave to be opened, and her husband really was inside it. I don't know what condition the body was in, but I think it probably did not smell very nice by then. Mrs. Pfeiff was happy to be able to take her husband home, though, so he could be buried in Illinois. Later on, she learned that her husband's dog had been with him when he died and had stayed by his grave for 12 days. He was a very loyal dog, and I hope he had a long and happy life back home in Illinois with Mrs. Pfeiff. Plus I still wish I knew what his name was.